Papers on tree growth rate vs. longevity, live fast – die young

Forest carbon sink neutralized by pervasive growth-lifespan trade-offs (Brienen et al. 2020) [OPEN ACCESS]. “Land vegetation is currently taking up large amounts of atmospheric CO₂, possibly due to tree growth stimulation. Extant models predict that this growth stimulation will continue to cause a net carbon uptake this century. However, there are indications that increased growth rates may shorten trees′ lifespan and thus recent increases in forest carbon stocks may be transient due to lagged increases in mortality. Here we show that growth-lifespan trade-offs are indeed near universal, occurring across almost all species and climates. This trade-off is directly linked to faster growth reducing tree lifespan, and not due to covariance with climate or environment. Thus, current tree growth stimulation will, inevitably, result in a lagged increase in canopy tree mortality, as is indeed widely observed, and eventually neutralise carbon gains due to growth stimulation. Results from a strongly data-based forest simulator confirm these expectations. Extant Earth system model projections of global forest carbon sink persistence are likely too optimistic, increasing the need to curb greenhouse gas emissions.” Brienen, R.J.W., Caldwell, L., Duchesne, L. et al. Forest carbon sink neutralized by pervasive growth-lifespan trade-offs. Nat Commun 11, 4241 (2020). https://doi.org/10.1038/s41467-020-17966-z

Limited capacity of tree growth to mitigate the global greenhouse effect under predicted warming (Büntgen et al. 2019) [OPEN ACCESS]. “It is generally accepted that animal heartbeat and lifespan are often inversely correlated, however, the relationship between productivity and longevity has not yet been described for trees growing under industrial and pre-industrial climates. Using 1768 annually resolved and absolutely dated ring width measurement series from living and dead conifers that grew in undisturbed, high-elevation sites in the Spanish Pyrenees and the Russian Altai over the past 2000 years, we test the hypothesis of grow fast—die young. We find maximum tree ages are significantly correlated with slow juvenile growth rates. We conclude, the interdependence between higher stem productivity, faster tree turnover, and shorter carbon residence time, reduces the capacity of forest ecosystems to store carbon under a climate warming-induced stimulation of tree growth at policy-relevant timescales.” Büntgen, U., Krusic, P.J., Piermattei, A. et al. Limited capacity of tree growth to mitigate the global greenhouse effect under predicted warming. Nat Commun 10, 2171 (2019). https://doi.org/10.1038/s41467-019-10174-4

Temporal declines in tree longevity associated with faster lifetime growth rates in boreal forests (Searle & Chen, 2018) [OPEN ACCESS]. “Global change has been linked to significant increases in tree mortality in the world’s forests. Reduced tree longevity through increased growth rates has been suggested as one of the mechanisms responsible for the temporal increases in tree mortality, but this idea has not been directly tested. Here we explicitly defined two testable hypotheses: (i) the probability of ageing driven tree mortality increases with global change and (ii) the mortality probability associated with global change is higher for faster growing trees. To test these hypotheses, we examined the temporal changes of tree mortality probability in 539 permanent sample plots monitored from 1960–2009, with ages greater than 100 years at initial censuses, across the boreal region of Alberta, Canada. As expected, we found an overall temporal increase in tree mortality probability, indicating a loss in tree longevity with global change. We also found that trees with faster lifetime growth rates experienced higher temporal increases in mortality probability compared to slower growing trees. An analysis of the responses of tree mortality probability to increasing atmospheric carbon dioxide and temperature and decreases in water availability indicated that increasing atmospheric carbon dioxide and decreasing water availability were the major drivers of declining longevity. Our results suggest that tree longevity may further decline with the expected increase of atmospheric carbon dioxide and decreasing water availability in the region.” Eric B Searle and Han Y H Chen 2018 Environ. Res. Lett. 13 125003. https://doi.org/10.1088/1748-9326/aaea9e

The longevity of broadleaf deciduous trees in Northern Hemisphere temperate forests: insights from tree-ring series (Di Filippo et al. 2015) [OPEN ACCESS]. “Understanding the factors controlling the expression of longevity in trees is still an outstanding challenge for tree biologists and forest ecologists. We gathered tree-ring data and literature for broadleaf deciduous (BD) temperate trees growing in closed-canopy old-growth (OG) forests in the Northern Hemisphere to explore the role of geographic patterns, climate variability, and growth rates on longevity. Our pan-continental analysis, covering 25 species from 12 genera, showed that 300–400 years can be considered a baseline threshold for maximum tree lifespan in many temperate deciduous forests. Maximum age varies greatly in relation to environmental features, even within the same species. Tree longevity is generally promoted by reduced growth rates across large genetic differences and environmental gradients. We argue that slower growth rates, and the associated smaller size, provide trees with an advantage against biotic and abiotic disturbance agents, supporting the idea that size, not age, is the main constraint to tree longevity. The oldest trees were living most of their life in subordinate canopy conditions and/or within primary forests in cool temperate environments and outside major storm tracks. Very old trees are thus characterized by slow growth and often live in forests with harsh site conditions and infrequent disturbance events that kill much of the trees. Temperature inversely controls the expression of longevity in mesophilous species (Fagus spp.), but its role in Quercus spp. is more complex and warrants further research in disturbance ecology. Biological, ecological, and historical drivers must be considered to understand the constraints imposed to longevity within different forest landscapes.” Alfredo Di Filippo, Neil Pederson, Michele Baliva, Michele Brunetti, Anna Dinella, Keiko Kitamura, Hanns D. Knapp, Bartolomeo Schirone, Gianluca Piovesan (2015). Front. Ecol. Evol., Sec. Paleoecology 3(15 May 2015). https://doi.org/10.3389/fevo.2015.00046

Slow lifelong growth predisposes Populus tremuloides trees to mortality (Ireland et al. 2014) [FULL TEXT]. “Widespread dieback of aspen forests, sometimes called sudden aspen decline, has been observed throughout much of western North America, with the highest mortality rates in the southwestern United States. Recent aspen mortality has been linked to drought stress and elevated temperatures characteristic of conditions expected under climate change, but the role of individual aspen tree growth patterns in contributing to recent tree mortality is less well known. We used tree-ring data to investigate the relationship between an individual aspen tree’s lifetime growth patterns and mortality. Surviving aspen trees had consistently higher average growth rates for at least 100 years than dead trees. Contrary to observations from late successional species, slow initial growth rates were not associated with a longer lifespan in aspen. Aspen trees that died had slower lifetime growth and slower growth at various stages of their lives than those that survived. Differences in average diameter growth between live and dead trees were significant (α = 0.05) across all time periods tested. Our best logistical model of aspen mortality indicates that younger aspen trees with lower recent growth rates and higher frequencies of abrupt growth declines had an increased risk of mortality. Our findings highlight the need for species-specific mortality functions in forest succession models. Size-dependent mortality functions suitable for late successional species may not be appropriate for species with different life history strategies. For some early successional species, like aspen, slow growth at various stages of the tree’s life is associated with increased mortality risk.” Ireland, K.B., Moore, M.M., Fulé, P.Z. et al. Slow lifelong growth predisposes Populus tremuloides trees to mortality. Oecologia 175, 847–859 (2014). https://doi.org/10.1007/s00442-014-2951-5

Extreme longevity in trees: live slow, die old? (Issartel & Coiffard, 2011). “We have examined the extreme longevity displayed by trees in relation to a theory mainly developed in animals, namely, the controversial rate of living (ROL) theory of aging which proposes that longevity is negatively correlated to metabolic rate. Plant metabolism implies respiration and photosynthesis; both are susceptible to negatively impact longevity. The relationship between longevity and metabolism was studied in leaves and stems of several species with the aim of challenging the ROL theory in trees. Leaf and stem life spans were found to be highly correlated to metabolism (R ² = 0.97), and stems displayed a much lower metabolism than leaves. Analysis of covariance (ANCOVA), with metabolism as the covariate, revealed no difference between mean leaf and stem life spans, which would appear to conform to the expectations of the ROL theory. Consequently, the extremely high longevity of trees may be explained by the lower metabolism displayed by the stems. These results clearly reflect different energy allocation and energy expenditure rate strategies between leaves and stems, which may result in different senescence rates (and life spans) in these organs. They also suggest that, in contrast to animals, the ROL theory of aging may apply to woody plants at the organ level, thereby opening a promising new line of research to guide future studies on plant senescence.” Issartel, J., Coiffard, C. Extreme longevity in trees: live slow, die old?. Oecologia 165, 1–5 (2011). https://doi.org/10.1007/s00442-010-1807-x

Will the CO2 fertilization effect in forests be offset by reduced tree longevity? (Bugmann & Bigler, 2010) [FULL TEXT]. “Experimental studies suggest that tree growth is stimulated in a greenhouse atmosphere, leading to faster carbon accumulation (i.e., a higher rate of gap filling). However, higher growth may be coupled with reduced longevity, thus leading to faster carbon release (i.e., a higher rate of gap creation). The net effect of these two counteracting processes is not known. We quantify this net effect on aboveground carbon stocks using a novel combination of data sets and modeling. Data on maximum growth rate and maximum longevity of 141 temperate tree species are used to derive a relationship between growth stimulation and changes in longevity. We employ this relationship to modify the respective parameter values of tree species in a forest succession model and study aboveground biomass in a factorial design of growth stimulation × reduced maximum longevity at multiple sites along a climate gradient from the cold to the dry treeline. The results show that (1) any growth stimulation at the tree level leads to a disproportionately small increase of stand biomass due to negative feedback effects, even in the absence of reduced longevity; (2) a reduction of tree longevity tends to offset the growth-related biomass increase; at the most likely value of reduced longevity, the net effect is very close to zero in most multi- and single-species simulations; and (3) when averaging the response across all sites to mimic a “landscape-level” response, the net effect is close to zero. Thus, it is important to consider ecophysiological responses with their linkage to demographic processes in forest trees if one wishes to avoid erroneous inference at the ecosystem level. We conclude that any CO₂ fertilization effect is quite likely to be offset by an associated reduction in the longevity of forest trees, thus strongly reducing the carbon mitigation potential of temperate forests.” Bugmann, H., Bigler, C. Will the CO₂ fertilization effect in forests be offset by reduced tree longevity?. Oecologia 165, 533–544 (2011). https://doi.org/10.1007/s00442-010-1837-4

Functional traits and the growth–mortality trade-off in tropical trees (Wright et al. 2010) [FULL TEXT]. “A trade-off between growth and mortality rates characterizes tree species in closed canopy forests. This trade-off is maintained by inherent differences among species and spatial variation in light availability caused by canopy-opening disturbances. We evaluated conditions under which the trade-off is expressed and relationships with four key functional traits for 103 tree species from Barro Colorado Island, Panama. The trade-off is strongest for saplings for growth rates of the fastest growing individuals and mortality rates of the slowest growing individuals (r² = 0.69), intermediate for saplings for average growth rates and overall mortality rates (r² = 0.46), and much weaker for large trees (r² ≤ 0.10). This parallels likely levels of spatial variation in light availability, which is greatest for fast- vs. slow-growing saplings and least for large trees with foliage in the forest canopy. Inherent attributes of species contributing to the trade-off include abilities to disperse, acquire resources, grow rapidly, and tolerate shade and other stresses. There is growing interest in the possibility that functional traits might provide insight into such ecological differences and a growing consensus that seed mass (SM), leaf mass per area (LMA), wood density (WD), and maximum height (H_max) are key traits among forest trees. Seed mass, LMA, WD, and H_max are predicted to be small for light-demanding species with rapid growth and mortality and large for shade-tolerant species with slow growth and mortality. Six of these trait–demographic rate predictions were realized for saplings; however, with the exception of WD, the relationships were weak (r² < 0.1 for three and r² < 0.2 for five of the six remaining relationships). The four traits together explained 43–44% of interspecific variation in species positions on the growth–mortality trade-off; however, WD alone accounted for >80% of the explained variation and, after WD was included, LMA and H_max made insignificant contributions. Virtually the full range of values of SM, LMA, and H_max occurred at all positions on the growth–mortality trade-off. Although WD provides a promising start, a successful trait-based ecology of tropical forest trees will require consideration of additional traits.” Wright, S.J., Kitajima, K., Kraft, N.J.B., Reich, P.B., Wright, I.J., Bunker, D.E., Condit, R., Dalling, J.W., Davies, S.J., Díaz, S., Engelbrecht, B.M.J., Harms, K.E., Hubbell, S.P., Marks, C.O., Ruiz-Jaen, M.C., Salvador, C.M. and Zanne, A.E. (2010), Functional traits and the growth–mortality trade-off in tropical trees. Ecology, 91: 3664-3674. https://doi.org/10.1890/09-2335.1

Increased early growth rates decrease longevities of conifers in subalpine forests (Bigler & Veblen, 2009) [FULL TEXT]. “For trees, fast growth rates and large size seem to be a fitness benefit because of increased competitiveness, attainment of reproductive size earlier, reduction of generation times, and increased short-term survival chances. However, fast growth rates and large size entail reduced investment in defenses, lower wood density and mechanical strength, increased hydraulic resistance as well as problems with down-regulation of growth during periods of stress, all of which may decrease tree longevity. In this study, we investigated the relationship between longevity and growth rates of trees and quantified effects of spatial environmental variation (elevation, slope steepness, aspect, soil depth) on tree longevity. Radial growth rates and longevities were determined from tree-ring samples of 161 dead trees from three conifer species in subalpine forests of the Colorado Rocky Mountains (Abies lasiocarpa, Picea engelmannii) and the Swiss Alps (Picea abies). For all three species, we found an apparent tradeoff between growth rate to the age of 50 years and longevity (i.e. fast early growth is associated with decreased longevity). This association was particularly pronounced for larger P. engelmannii and P. abies, which attained canopy size, however, there were also significant effects for smaller P. engelmannii and P. abies. For the more shade-tolerant A. lasiocarpa, tree size did not have any effect. Among the abiotic variables tested only northerly aspect significantly favored longevity of A. lasiocarpa and P. engelmannii. Trees growing on south-facing aspects probably experience greater water deficits leading to premature tree death, and/or shorter life spans may reflect shorter fire intervals on these more xeric aspects. Empirical evidence from other studies has shown that global warming affects growth rates of trees over large spatial and temporal scales. For moist-cool subalpine forests, we hypothesize that the higher growth rates associated with global warming may in turn result in reduced tree longevity and more rapid turnover rates.” Bigler, C. and Veblen, T.T. (2009), Increased early growth rates decrease longevities of conifers in subalpine forests. Oikos, 118: 1130-1138. https://doi.org/10.1111/j.1600-0706.2009.17592.x

Age class, longevity and growth rate relationships: protracted growth increases in old trees in the eastern United States (Johnson & Abrams, 2009) [OPEN ACCESS]. “This study uses data from the International Tree-Ring Data Bank website and tree cores collected in the field to explore growth rate (basal area increment, BAI) relationships across age classes (from young to old) for eight tree species in the eastern US. These species represent a variety of ecological traits and include those in the genera Populus, Quercus, Pinus, Tsuga and Nyssa. We found that most trees in all age classes and species exhibit an increasing BAI throughout their lives. This is particularly unusual for trees in the older age classes that we expected to have declining growth in the later years, as predicted by physiological growth models. There exists an inverse relationship between growth rate and increasing age class. The oldest trees within each species have consistently slow growth throughout their lives, implying an inverse relationship between growth rate and longevity. Younger trees (< 60 years of age) within each species are consistently growing faster than the older trees when they are of the same age resulting from a higher proportion of fast-growing trees in these young age classes. Slow, but increasing, BAI in the oldest trees in recent decades is a continuation of their growth pattern established in previous centuries. The fact that they have not shown a decreasing growth rate in their old age contradicts physiological growth models and may be related to the stimulatory effects of global change phenomenon (climate and land-use history).” Sarah E. Johnson, Marc D. Abrams, Age class, longevity and growth rate relationships: protracted growth increases in old trees in the eastern United States, Tree Physiology, Volume 29, Issue 11, November 2009, Pages 1317–1328, https://doi.org/10.1093/treephys/tpp068

Relationships between radial growth rates and lifespan within North American tree species (Black et al. 2008) [FULL TEXT]. “We conducted a meta-analysis of tree-ring data to quantify relationships between growth and lifespan in 4 North American tree species: Tsuga canadensis, Quercus alba, Pinus ponderosa, and Pseudotsuga menziesii. Data sets were compiled from across the range of each species and included a total of 14 341 measured time series. For each species we calculated the age at which each tree was sampled and pooled all trees into 50-y bins. Within each of these 50-y bins, we calculated mean ring width and mean basal area increment in 50-y intervals according to cambial age. Thus, ring widths formed during the same time period in the trees’ life stage could be compared across trees sampled at increasing ages. In all 4 species the longest-lived trees experienced slower growth rates than trees sampled at relatively young ages. Furthermore, long-lived trees with slow growth rates appear to mix with shorter-lived, fast-growing trees in the same forests. Such a relationship between growth and lifespan within species may be an important component of biodiversity that holds implications for old-growth forest development and long-term management.” Bryan A. Black, Jim J. Colbert & Neil Pederson (2008) Relationships between radial growth rates and lifespan within North American tree species, Écoscience, 15:3, 349-357, https://doi.org/10.2980/15-3-3149

Papers on how longwave radiation warms oceans

The Impact of Wind Gusts on the Ocean Thermal Skin Layer – Zappa et al. (2019) “The thermodynamic and emissive properties of the ocean thermal skin layer are crucial contributors to air‐sea heat flux. In order to properly observe ocean surface temperature without disturbing any delicate fluid mechanical processes, thermal infrared imaging is often used. However, wind impacting the ocean surface complicates the extraction of meaningful information from thermal imagery; this is especially true for transient forcing phenomena such as wind gusts. Here, we describe wind gust‐water surface interaction through its impact on skin layer thermal and emissive properties. Two key physical processes are identified: (1) the growth of centimeter‐scale wind waves, which increases interfacial emissivity, and (2) microscale wave breaking and shear, which mix the cool skin layer with warmer millimeter‐depth water and increase the skin temperature. As more observations are made of air‐sea interaction under transient forcing, the full consideration of these processes becomes increasingly important.” Zappa, C. J., Laxague, N. J. M., Brumer, S. E., & Anderson, S. P. (2019). The impact of wind gusts on the ocean thermal skin layer. Geophysical Research Letters, 46, 11301– 11309. https://doi.org/10.1029/2019GL083687. [FULL TEXT]

The Response of the Ocean Thermal Skin Layer to Variations in Incident Infrared Radiation – Wong & Minnett (2018) “Ocean warming trends are observed and coincide with the increase in concentrations of greenhouse gases in the atmosphere resulting from human activities. At the ocean surface, most of the incoming infrared (IR) radiation is absorbed within the top micrometers of the ocean’s surface where the thermal skin layer (TSL) exists. Thus, the incident IR radiation does not directly heat the upper few meters of the ocean. This paper investigates the physical mechanism between the absorption of IR radiation and its effect on heat transfer at the air‐sea boundary. The hypothesis is that given the heat lost through the air‐sea interface is controlled by the TSL, the TSL adjusts in response to variations in incident IR radiation to maintain the surface heat loss. This modulates the flow of heat from below and hence controls upper ocean heat content. This hypothesis is tested using the increase in incoming longwave radiation from clouds and analyzing vertical temperature profiles in the TSL retrieved from sea‐surface emission spectra. The additional energy from the absorption of increasing IR radiation adjusts the curvature of the TSL such that the upward conduction of heat from the bulk of the ocean into the TSL is reduced. The additional energy absorbed within the TSL supports more of the surface heat loss. Thus, more heat beneath the TSL is retained leading to the observed increase in upper ocean heat content.” Wong, E. W., & Minnett, P. J. (2018). The response of the ocean thermal skin layer to variations in incident infrared radiation. Journal of Geophysical Research: Oceans, 123, 2475‐ 2493. https://doi.org/10.1002/2017JC013351. [FULL TEXT]

Bulk Parameterization of Air-Sea Exchanges of Heat and Water Vapor Including the Molecular Constraints at the Interface – Liu et al. (1979) “A model is developed for the marine atmospheric surface layer including the interfacial sublayers on both sides of the air-sea interface where molecular constraints on transports are important. Flux-profile relations which are based on the postulation of intermittent renewal of the surface fluid aye matched to the logarithmic profiles and compared with both field and laboratory measurements. These relations enable numerical determination of air-sea exchanges of momentum, heat and water vapor (or bulk transfer coefficients) employing the bulk parameters of mean wind speed, temperature and humidity at a certain height in the atmospheric surface layer, and the water temperature. With increasing wind speed, the flow goes from smooth to rough and the bulk transfer coefficient for momentum also increases. The increase in roughness is associated with increasing wave height which in the present model results in sheltering at the wave troughs. Due to the decrease in turbulent transports, the transfer coefficients of heat and water vapor decrease slightly with wind speed after the wind speed exceeds a certain value. The bulk transfer coefficients are also found to decrease with increasing stability. If the “bucket temperature” which typically gives the water temperature a few centimeters below the surface is used, rather than the interfacial temperature, erroneous results may be obtained when the air-sea temperature difference is small. By including the effects of stability and interfacial conditions in bulk parameterization, the model provides a way to account for physical conditions which are known to affect air-sea exchanges.” Liu, W. T., Katsaros, K. B., & Businger, J. A. (1979). Bulk Parameterization of Air-Sea Exchanges of Heat and Water Vapor Including the Molecular Constraints at the Interface, Journal of Atmospheric Sciences, 36(9), 1722-1735. https://doi.org/10.1175/1520-0469(1979)036<1722:BPOASE>2.0.CO;2. [FULL TEXT]

Heat thermal structure in the interfacial boundary layer measured in an open tank of water in turbulent free convection – Katsaros et al. (1977) “The thermal structure in the boundary layer and its relation to the heat flux from the cooling and evaporating surface of a deep tank of water are investigated. When a deep layer of water in contact with still air above loses heat to the air, the cooled water in a region just under the surface converges along lines and then plunges down in sheets. These sheets of falling water dissipate as they move into the body of the water, which is in turbulent motion. The vertical profiles of the horizontally averaged temperature and its standard deviation agree fairly closely with theoretical profiles based on time averages of the solution to the heat diffusion equation. The differences between observed and thus predicted profile shapes are consistent with the expected effects of the falling cold thermals and the warm return flow, which are neglected in the theories. The profiles of the standard deviation have large values up to the interface and lie between predictions based on boundary conditions of constant surface temperature and constant heat flux, in keeping with the experimental conditions. The relation between the net heat flux and the temperature difference across the boundary layer is given in non-dimensional form by N = 0[sdot ]156R^{0[sdot ]33}, which is in good agreement with the asymptotic similarity prediction N [vprop ] R1/3 but lower than theoretical calculations of the upper bound of N vs. R.” Katsaros, K., Liu, W., Businger, J., & Tillman, J. (1977). Heat thermal structure in the interfacial boundary layer measured in an open tank of water in turbulent free convection. Journal of Fluid Mechanics, 83(2), 311-335. doi:10.1017/S0022112077001219. [FULL TEXT]

Air-sea bulk transfer coefficients in diabatic conditions – Kondo (1975) “On the basis of recent data for the roughness Reynolds number of the sea surface, and using the Owen-Thomson theory on the transfers of heat and mass between a rough surface and the flow above it, the bulk transfer coefficients of the sea surface have been estimated. For a reference height of 10 m, the neutral-lapse transfer coefficient for water vapor is larger by only a few percent than that for sensible heat. When the wind speed at the 10-m height is u ₁₀>3 m s⁻¹, the coefficient for sensible heat C _H is larger by about 10% than that for momentum C _D . For u ₁₀<5 m s⁻¹, however, the value of C _D exceeds the value of C _H , and for u ₁₀=15 m s⁻¹ it is shown that C _H ≈0.8C _D . It may be also proposed that 10³ C _D =1.11 to 1.70, 10³ C _E =1.18 to 1.30, and 10³ C _H =1.15 to 1.26 for a range of u ₁₀=4 to 20 m s⁻¹. A plot of diabatic transfer coefficients versus wind speed is obtained by using a parameter of the sea-air temperature difference. For practical purposes, the coefficients are approximated by empirical formulae.” Kondo, J. Air-sea bulk transfer coefficients in diabatic conditions. Boundary-Layer Meteorol 9, 91–112 (1975). https://doi.org/10.1007/BF00232256.

Papers on COVID-19 and climate change

Quantifying the influence of short-term emission reductions on climate (Fyfe et al. 2021). “These estimates reveal the modest impact that temporary emission reductions associated with the COVID-19 pandemic will have on global and regional climate. Our simulations suggest that the impact of carbon dioxide and aerosol emission reductions is actually a temporary enhancement in warming rate. However, our results demonstrate that even large emission reductions applied for a short duration have only a small and likely undetectable impact.” J. C. Fyfe, V. Kharin, N. Swart, G. M. Flato, M. Sigmond, N. P. Gillett (2021). Science Advances 7(10):eabf7133.
https://doi.org/10.1126/sciadv.abf7133

The Climate Response to Emissions Reductions Due to COVID-19: Initial Results From CovidMIP (Jones et al. 2021). “We find model consensus on reduced aerosol amounts (particularly over southern and eastern Asia) and associated increases in surface shortwave radiation levels. However, any impact on near-surface temperature or rainfall during 2020–2024 is extremely small and is not detectable in this initial analysis.” Jones, C. D., Hickman, J. E., Rumbold, S. T., Walton, J., Lamboll, R. D., Skeie, R. B., et al. (2021). The climate response to emissions reductions due to COVID-19: Initial results from CovidMIP. Geophysical Research Letters, 48, e2020GL091883. https://doi.org/10.1029/2020GL091883

Climate Impacts of COVID‐19 Induced Emission Changes (Gettelman et al. 2021). “The average overall Effective Radiative Forcing (ERF) peaks at +0.29 ± 0.15 Wm⁻² in spring 2020.” … “However, the aerosol changes are the largest contribution to radiative forcing and temperature changes as a result of COVID‐19 affected emissions, larger than ozone, CO₂ and contrail effects.” Gettelman, A., Lamboll, R., Bardeen, C. G., Forster, P. M., & Watson‐Parris, D. (2021). Climate impacts of COVID‐19 induced emission changes. Geophysical Research Letters, 48, e2020GL091805. https://doi.org/10.1029/2020GL091805

Current and future global climate impacts resulting from COVID-19 (Forster et al. 2020). “As a result, we estimate that the direct effect of the pandemic-driven response will be negligible, with a cooling of around 0.01 ± 0.005 °C by 2030 compared to a baseline scenario that follows current national policies.” Forster, P.M., Forster, H.I., Evans, M.J. et al. Current and future global climate impacts resulting from COVID-19. Nat. Clim. Chang. 10, 913–919 (2020). https://doi.org/10.1038/s41558-020-0883-0

Satellite-based estimates of decline and rebound in China’s CO₂ emissions during COVID-19 pandemic (Zheng et al. 2020). “Between January and April 2020, China’s CO₂ emissions fell by 11.5% compared to the same period in 2019, but emissions have since rebounded to pre-pandemic levels before the coronavirus outbreak at the beginning of January 2020 owing to the fast economic recovery in provinces where industrial activity is concentrated.” Bo Zheng, Guannan Geng, Philippe Ciais, Steven J. Davis, Randall V. Martin et al. (2020). Science Advances 6(49):eabd4998. DOI: 10.1126/sciadv.abd4998

Fast Climate Responses to Aerosol Emission Reductions During the COVID‐19 Pandemic (Yang et al. 2020). “Assuming emission changes during lockdown, back‐to‐work and post‐lockdown stages of COVID‐19, climate model simulations show a surface warming over continental regions of the Northern Hemisphere. In January–March, there was an anomalous warming of 0.05–0.15 K in eastern China, and the surface temperature increase was 0.04–0.07 K in Europe, eastern United States, and South Asia in March–May.” Yang, Y., Ren, L., Li, H., Wang, H., Wang, P., Chen, L., et al. (2020). Fast climate responses to aerosol emission reductions during the COVID‐19 pandemic. Geophysical Research Letters, 47, e2020GL089788. https://doi.org/10.1029/2020GL089788

Minimal Climate Impacts From Short‐Lived Climate Forcers Following Emission Reductions Related to the COVID‐19 Pandemic (Weber et al. 2020). “Overall, the changes in ozone and aerosol direct effects (neglecting aerosol‐cloud interactions which were statistically insignificant but whose response warrants future investigation) yield a radiative forcing of −33 to −78 mWm⁻².” Weber, J., Shin, Y. M., Staunton Sykes, J., Archer‐Nicholls, S., Abraham, N. L., & Archibald, A. T. (2020). Minimal climate impacts from short‐lived climate forcers following emission reductions related to the COVID‐19 pandemic. Geophysical Research Letters, 47, e2020GL090326. https://doi.org/10.1029/2020GL090326

Near-real-time monitoring of global CO₂ emissions reveals the effects of the COVID-19 pandemic (Liu et al. 2020). “The key result is an abrupt 8.8% decrease in global CO₂ emissions (−1551 Mt CO₂) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic’s effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted,…” Liu, Z., Ciais, P., Deng, Z. et al. Near-real-time monitoring of global CO₂ emissions reveals the effects of the COVID-19 pandemic. Nat Commun 11, 5172 (2020). https://doi.org/10.1038/s41467-020-18922-7

Temporary reduction in daily global CO₂ emissions during the COVID-19 forced confinement (Le Quéré et al. 2020). “Daily global CO₂ emissions decreased by –17% (–11 to –25% for ±1σ) by early April 2020 compared with the mean 2019 levels, just under half from changes in surface transport. At their peak, emissions in individual countries decreased by –26% on average.” Le Quéré, C., Jackson, R.B., Jones, M.W. et al. Temporary reduction in daily global CO₂ emissions during the COVID-19 forced confinement. Nat. Clim. Chang. 10, 647–653 (2020). https://doi.org/10.1038/s41558-020-0797-x

List of Papers on Global Warming Hiatus, v2.0 (308 papers)

I have updated my list of papers on global warming hiatus to include papers published during 2017. There are also a few additions of earlier published papers.

The paper count is now 308.

The list can be downloaded from ResearchGate:

List of Global Warming Hiatus Papers, version 2
https://www.researchgate.net/publication/329982489_List_of_Global_Warming_Hiatus_Papers_version_2

DOI: 10.13140/RG.2.2.29065.70241

New research, September 5, 2015

Some new papers from last few days:

Dramatically increased rate of observed hot record-breaking in recent Australian temperatures
http://onlinelibrary.wiley.com/doi/10.1002/2015GL065793/abstract

Ice thickness in the Northwest Passage
http://onlinelibrary.wiley.com/doi/10.1002/2015GL065704/abstract

Positive tropical marine low-cloud cover feedback inferred from cloud-controlling factors
http://onlinelibrary.wiley.com/doi/10.1002/2015GL065627/abstract

Evidence for Weakening of the Walker Circulation from Cloud Observations
http://onlinelibrary.wiley.com/doi/10.1002/2015GL065463/abstract

Positive feedback in climate: stabilization or runaway, illustrated by a simple experiment
http://journals.ametsoc.org/doi/abs/10.1175/BAMS-D-14-00022.1

Need for Caution in Interpreting Extreme Weather Statistics
http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-15-0020.1

Quantifying the resolution level where the GRACE satellites can separate Greenland’s glacial mass balance from surface mass balance (open access)
http://www.the-cryosphere.net/9/1761/2015/tc-9-1761-2015.html

Complementing thermosteric sea level rise estimates (open access)
http://www.geosci-model-dev.net/8/2723/2015/gmd-8-2723-2015.html

Is there a solar signal in lower stratospheric water vapour? (open access)
http://www.atmos-chem-phys.net/15/9851/2015/acp-15-9851-2015.html

Ocean heat content variability and change in an ensemble of ocean reanalyses (open access)
http://link.springer.com/article/10.1007%2Fs00382-015-2801-0

Irreducible uncertainty in near-term climate projections (open access)
http://link.springer.com/article/10.1007%2Fs00382-015-2806-8

Using historical climate observations to understand future climate change crop yield impacts in the Southeastern US
http://rd.springer.com/article/10.1007%2Fs10584-015-1497-9

Scientific advocacy, environmental interest groups, and climate change: are climate skeptic portrayals of climate scientists as biased accurate?
http://rd.springer.com/article/10.1007%2Fs10584-015-1477-0

Impacts of climate change on the hydrology of two Natura 2000 sites in Northern Greece
http://link.springer.com/article/10.1007%2Fs10113-015-0857-3

Exploring the economic case for climate action in cities
http://www.sciencedirect.com/science/article/pii/S0959378015300169

Permafrost hydrology in changing climatic conditions: seasonal variability of stable isotope composition in rivers in discontinuous permafrost (open access)
http://iopscience.iop.org/article/10.1088/1748-9326/10/9/095003/meta

Climate change impacts on US agriculture and forestry: benefits of global climate stabilization (open access)
http://iopscience.iop.org/article/10.1088/1748-9326/10/9/095004/meta

New research – December 2014

Some selected papers as included in my New research stream in Twitter and in Facebook during December 2014. There are 127 papers, which makes it about 4.1 papers per day.

CLIMATE SCIENCE

Early twentieth-century warming linked to tropical Pacific wind strength ABSTRACT
Removing diurnal cycle contamination in satellite-derived tropospheric temperatures: Understanding tropical tropospheric trend discrepancies ABSTRACT
Long-term changes in summer temperature anomaly patterns in Japan since the early 20th century ABSTRACT
Time irreversibility of mean temperature anomaly variations over China ABSTRACT
Changes to the temporal distribution of daily precipitation ABSTRACT
The Oslo temperature series 1837–2012: homogeneity testing and temperature analysis ABSTRACT
Decadal variability of clouds, solar radiation and temperature at a high-latitude coastal site in Norway (open access) ABSTRACT
Using land cover, population and night light data for assessing local temperature differences in Mainz, Germany ABSTRACT
Is the Monthly Temperature Climate of the United States Becoming More Extreme? ABSTRACT
Variations in extreme temperature and precipitation for a Caribbean island: Trinidad ABSTRACT
World’s greatest rainfall intensities observed by satellites ABSTRACT
Changing characteristics of precipitation during 1960–2012 in Inner Mongolia, northern China ABSTRACT
Hierarchical analysis of rainfall variability across Nigeria ABSTRACT
Small lakes show muted climate change signal in deep-water temperatures ABSTRACT
Spectral signatures of Earth’s climate variability over 5 years from IASI ABSTRACT
Sensitivity of climate to cumulative carbon emissions due to compensation of ocean heat and carbon uptake ABSTRACT
Maximum warming occurs about one decade after a carbon dioxide emission (open access) ABSTRACT
Understanding the systematic air temperature biases in a coupled climate system model through a process-based decomposition method ABSTRACT
Feedback attribution of the land-sea warming contrast in a global warming simulation of the NCAR CCSM4 (open access) ABSTRACT
Relationship between sunshine duration and air temperature and contemporary global warming ABSTRACT
Seasonal cycle and long-term trend of solar energy fluxes through Arctic sea ice (open access) ABSTRACT
Effects of Arctic haze on surface cloud radiative forcing ABSTRACT
On the role of sulfates in recent global warming: a Granger causality analysis ABSTRACT
Observed multi-variable signals of late 20th and early 21st century volcanic activity ABSTRACT
Evaluating biases in simulated snow albedo feedback in two generations of climate models ABSTRACT
Potential climate forcing of land use and land cover change (open access) ABSTRACT
Assessing climatic impacts of future land use and land cover change projected with the CanESM2 model ABSTRACT
Biogeophysical impacts of peatland forestation on regional climate changes in Finland (open access) ABSTRACT
Arctic greening can cause earlier seasonality of Arctic amplification ABSTRACT
The extreme drought episode of August 2011–May 2012 in the Czech Republic ABSTRACT
How unusual is the 2012-2014 California drought? ABSTRACT
Global Warming and Changes in Risk of Concurrent Climate Extremes: Insights from the 2014 California Drought ABSTRACT
Investigating uncertainties in global gridded datasets of climate extremes (open access) ABSTRACT
Cold extremes in North America vs. mild weather in Europe: the winter 2013/2014 in the context of a warming world (open access) ABSTRACT
Future increase of super-typhoon intensity associated with climate change ABSTRACT
The effect of global warming on severe thunderstorms in the United States ABSTRACT
Fatalities of neglect: adapt to more intense hurricanes under global warming? ABSTRACT
Are Special Processes At Work in the Rapid Intensification of Tropical Cyclones? ABSTRACT
Return periods of losses associated with European windstorm series in a changing climate (open access) ABSTRACT
The impact of natural and anthropogenic climate change on Western North Pacific tropical cyclone tracks ABSTRACT
Understanding the El Niño-like oceanic response in the tropical Pacific to global warming ABSTRACT
ENSO influence upon global temperature in nature and in CMIP5 simulations ABSTRACT
The Curious Case of the El Niño That Never Happened: A perspective from 40 years of progress in climate research and forecasting (open access) ABSTRACT
Land surface anomalies preceding the 2010 Russian heat wave and a link to the North Atlantic oscillation (open access) ABSTRACT
The effect of the North Atlantic Oscillation on the Iraqi climate 1982–2000 ABSTRACT
Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies (open access) ABSTRACT
Stratospheric ozone depletion from future nitrous oxide increases (open access) ABSTRACT
The impact of polar stratospheric ozone loss on Southern Hemisphere stratospheric circulation and climate (open access) ABSTRACT
Is the present the key to the future? ABSTRACT
Practising historical climatology in West Africa: a climatic periodisation 1750–1800 ABSTRACT

CLIMATE CHANGE IMPACTS

Increasing temperature forcing reduces the Greenland Ice Sheet’s response time scale ABSTRACT
Assessing spatio-temporal variability and trends in modelled and measured Greenland Ice Sheet albedo (2000–2013) (open access) ABSTRACT
Subsurface imaging reveals a confined aquifer beneath an ice-sealed Antarctic lake ABSTRACT
Estimating the volume of glaciers in the Himalayan–Karakoram region using different methods (open access) ABSTRACT
Direct measurement of glacier thinning on the southern Tibetan Plateau (Gurenhekou, Kangwure and Naimona’Nyi glaciers) ABSTRACT
Deglaciation of the Caucasus Mountains, Russia/Georgia, in the 21st century observed with ASTER satellite imagery and aerial photography (open access) ABSTRACT
Post-LIA glacier changes along a latitudinal transect in the Central Italian Alps (open access) ABSTRACT
Glacier topography and elevation changes derived from Pléiades sub-meter stereo images (open access) ABSTRACT
Rapid dynamic activation of a marine-based Arctic ice cap ABSTRACT
Recent advances in understanding the Arctic climate system state and change from a sea ice perspective: a review (open access) ABSTRACT
Atmospheric Response in Summer linked to Recent Arctic Sea Ice Loss ABSTRACT
Reduced risk of North American cold extremes due to continued Arctic sea ice loss ABSTRACT
Observed and simulated changes in Antarctic sea ice extent over the past 50 years ABSTRACT
Temperature sensitivity as an explanation of the latitudinal pattern of green-up date trend in Northern Hemisphere vegetation during 1982–2008 ABSTRACT
No growth stimulation of tropical trees by 150 years of CO2 fertilization but water-use efficiency increased ABSTRACT
Greater deciduous shrub abundance extends tundra peak season and increases modeled net CO2 uptake ABSTRACT
Temperature-induced recruitment pulses of Arctic dwarf shrub communities ABSTRACT
Assessing phenological change and climatic control of alpine grasslands in the Tibetan Plateau with MODIS time series ABSTRACT
Determining the relative importance of climatic drivers on spring phenology in grassland ecosystems of semi-arid areas ABSTRACT
Climate-induced changes in host tree-insect phenology may drive ecological state-shift in boreal forest ABSTRACT
General patterns of acclimation of leaf respiration to elevated temperatures across biomes and plant types ABSTRACT
Fruitful factors: what limits seed production of flowering plants in the alpine? ABSTRACT
Latitudinal gradients in the productivity of European migrant warblers have not shifted northwards during a period of climate change ABSTRACT
Directionality of recent bird distribution shifts and climate change in Great Britain ABSTRACT
Drivers of trophic amplification of ocean productivity trends in a changing climate (open access) ABSTRACT
Limpets counteract ocean acidification induced shell corrosion by thickening of aragonitic shell layers (open access) ABSTRACT
Projected pH reductions by 2100 might put deep North Atlantic biodiversity at risk (open access) ABSTRACT
Galápagos Coral Reef Persistence after ENSO Warming Across an Acidification Gradient ABSTRACT
Detecting and understanding the accelerated sea level rise along the east coast of U.S. during recent decades ABSTRACT
How the AMOC affects ocean temperatures on decadal to centennial timescales: the North Atlantic versus an interhemispheric seesaw ABSTRACT
Global radiative adjustment after a collapse of the Atlantic meridional overturning circulation ABSTRACT
Critical elevation levels for flooding due to sea-level rise in Hawai‘i ABSTRACT
From the extreme to the mean: Acceleration and tipping points of coastal inundation from sea level rise (open access) ABSTRACT
Joint effects of storm surge and sea-level rise on US Coasts: new economic estimates of impacts, adaptation, and benefits of mitigation policy (open access) ABSTRACT
Multimodel simulations of Arctic Ocean sea surface height variability in the period 1970–2009 ABSTRACT
Climate change and sectors of the surface water cycle In CMIP5 projections (open access) ABSTRACT
Managing the Anthropocene marine transgression to the year 2100 and beyond in the State of Florida U.S.A. ABSTRACT
On the hiatus in the acceleration of tropical upwelling since the beginning of the 21st century (open access) ABSTRACT
Quantification of hydrologic impacts of climate change in a Mediterranean basin in Sardinia, Italy, through high-resolution simulations (open access) ABSTRACT
Responses of global terrestrial evapotranspiration to climate change and increasing atmospheric CO2 in the 21st century (open access) ABSTRACT
Diurnal temperature range and short-term mortality in large US communities ABSTRACT
Macro-economic cycles related to climate change in dynastic China ABSTRACT
Climate change and Chinese history: a review of trends, topics, and methods ABSTRACT
Association between climate factors and diarrhoea in a Mekong Delta area ABSTRACT

CLIMATE CHANGE MITIGATION AND ADAPTATION

Satellite-inferred European carbon sink larger than expected (open access) ABSTRACT
Estimated stocks of circumpolar permafrost carbon with quantified uncertainty ranges and identified data gaps (open access) ABSTRACT
Nitrogen availability reduces CMIP5 projections of 21st century land carbon uptake ABSTRACT
Observing terrestrial ecosystems and the carbon cycle from space ABSTRACT
Net regional methane sink in High Arctic soils of northeast Greenland ABSTRACT
Managing short-lived climate forcers in curbing climate change: an atmospheric chemistry synopsis ABSTRACT
Key role for nuclear energy in global biodiversity conservation (open access) ABSTRACT
China’s approach to nuclear safety — From the perspective of policy and institutional system ABSTRACT
Radioactivity impacts of the Fukushima Nuclear Accident on the atmosphere ABSTRACT
Effects of Climate Oscillations on Wind Resource Variability in the United States ABSTRACT
Climate change induced transformations of agricultural systems: insights from a global model (open access) ABSTRACT
The Role of Carbon Capture and Sequestration Policies for Climate Change Mitigation ABSTRACT
Increase in surface albedo caused by agricultural plastic film ABSTRACT
Stratospheric dynamics and midlatitude jets under geoengineering with space mirrors, and sulfate and titania aerosols ABSTRACT
Climate change: the necessary, the possible and the desirable (open access) ABSTRACT
Unilateral Climate Policies: Incentives and Effects ABSTRACT
Corruption and Climate Change Policies: Do the Bad Old Days Matter? ABSTRACT
Disentangling the ranges: climate policy scenarios for China and India ABSTRACT
People as sensors: Mass media and local temperature influence climate change discussion on Twitter ABSTRACT
Perceptions of climate change risk in four disaster-impacted rural Australian towns ABSTRACT
Social vulnerability in three high-poverty climate change hot spots: What does the climate change literature tell us? ABSTRACT
Five reasons why it is difficult to talk to Australian farmers about the impacts of, and their adaptation to, climate change ABSTRACT

PALAEOCLIMATE

Interaction of ice sheets and climate during the past 800 000 years (open access) ABSTRACT
Detecting long-term growth trends using tree rings: A critical evaluation of methods ABSTRACT
Early summer temperatures reconstructed from black pine (Pinus nigra Arnold) tree-ring widths from Albania ABSTRACT
Damaging hailstorms in South Moravia, Czech Republic, in the seventeenth to twentieth centuries as derived from taxation records ABSTRACT
Millennial meridional dynamics of the Indo-Pacific Warm Pool during the last termination (open access) ABSTRACT
Interdecadal Pacific variability and eastern Australian mega-droughts over the last millennium ABSTRACT
Two massive, rapid releases of carbon during the onset of the Palaeocene–Eocene thermal maximum ABSTRACT
Enhanced 20th-century heat transfer to the Arctic simulated in the context of climate variations over the last millennium (open access) ABSTRACT
Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present ABSTRACT

OTHERS

Detecting change in urban areas at continental scales with MODIS data ABSTRACT
Is the Anthropocene really worthy of a formal geologic definition? (open access) ABSTRACT

What doesn’t change with climate?

Global warming and subsequent climate change have a lot of different effects. The composition of the atmosphere changes. The troposphere swells and the atmosphere gets wetter. Oceans warm and expand. There are chemical changes in the ocean waters. Well known example of that is the ocean acidification caused by the increasing carbon dioxide concentration.

The biosphere gets shuffled. Some species shift to other places looking for more suitable conditions in which to live. Body shape and/or size changes for some species. The timetables between species get all mixed up. For example, because of an earlier spring the available food (caterpillars) is gone before the eggs of migratory birds hatch. Some, or according to predictions quite many, of the species will even go extinct.

Glaciers and ice sheets are melting. There are changes even in the lithosphere when the pressing weight of the ice sheets and glaciers is reduced as they melt into the ocean. Today at some places we can still see this same effect at work as the Earth’s crust is uplifting because the weight of the ice sheets that were there during the last glaciation (i.e. the “ice age”) was removed when the ice melted away. This effect also affects the asthenosphere, a viscous layer below the lithosphere.

So the climate change shows up everywhere – in the atmosphere, hydrosphere, biosphere, cryosphere, lithosphere, asthenosphere, and beyond. Is there anything within Earth’s system that doesn’t change with climate?