Climate of the Past, Present and Future. A scientific debate, 2nd ed.
Abstract
This book is an unorthodox ground-breaking scientific study on natural climate change and its contribution to ongoing multi-centennial global warming.
The book critically reviews the effect of the following on climate:
- Milankovitch cycles
- abrupt glacial (Dansgaard-Oeschger) events
- Holocene climate variability
- the 1500-year cycle
- solar activity
- volcanic eruptions
- greenhouse gases
- energy transport
Applying the scientific method to available evidence reveals that some of these phenomena are profoundly misunderstood by most researchers. Milankovitch cycles are tied to orbital obliquity, not to orbital precessional summer insolation; glacial megatides might have triggered abrupt Dansgaard-Oeschger events; and tides are likely responsible for the related 1500-year climate cycle. Climate change affects volcanic eruptions more than the opposite; and secular variations in solar activity are more important to climate change during the Holocene than greenhouse gases.
In this book, we see how important natural climate change has been on human societies of the past. It also produces new climate projections for the 21st century and when the next glaciation could happen.
What emerges from this study of natural climate change is a central theme:
Variations in the transport of energy from the tropics to the poles have been neglected as a cause of climate change, and solar activity variations affect climate by modulating this transport.
The author tells us: –Transporting more energy from a greenhouse gas-rich region, the tropics, to a greenhouse gas-poor region, the poles, increases the amount of energy lost at the top of the atmosphere. The effect resembles a reduction in the greenhouse gas content.–
The book presents the Winter-Gatekeeper Hypothesis on how variations in solar activity regulate Earth's energy transport and in so doing affect atmospheric circulation, the rotation of the planet, and the El Niño/Southern Oscillation.
This book is oriented toward students and academics in the climate sciences and climate anthropology and should also appeal to readers interested in the science of natural climate change. The repercussions of Climate of the Past, Present and Future are far reaching. By uncovering a strong natural climate change component, it provides a novel view of anthropogenic climate change, fossil energy use, and our future climate; a view quite different from the IPCC's gloomy projections.
... The Pacific Decadal Oscillation reverted to predominantly negative values, indicating a shift in the frequency of El Niño-Southern Oscillation events. The Hadley cells began to expand and intensify, extratropical low cloud cover experienced a sudden decrease, surface wind speeds over Europe increased, and the Arctic began to warm rapidly during winter (Vinós, 2022(Vinós, , 2023. ...
... A recently proposed hypothesis of natural climate change, known as the Winter Gatekeeper, is based on variations in meridional heat transport and the differing strength of the greenhouse effect between tropical and polar regions (Vinós, 2022(Vinós, , 2023. This hypothesis emphasizes the critical role of planetary Rossby waves in modulating the strength of the polar vortex during winter. ...
... The most recent two tipping points at which the global atmospheric system transitioned from one regime to another are well-established in the data, occurring around the years 1976 ± 1 and 1997 ± 1. These dates have been identified in numerous studies as inflection points in the trends of various climate variables (Vinós, 2022(Vinós, , 2023, including those illustrated in Figure 13.14. In the case of Antarctic ozone, a noticeable shift in its trend can also be observed near one of these dates. ...
Forty years have passed since the signing of the Vienna Convention for the Protection of the Ozone Layer on March 22, 1985. This Convention provided the necessary framework for the creation of the regulatory measures and monitoring bodies required for the Montreal Protocol, agreed on September 16, 1987. It is one of the most successful treaties in history, having been ratified by198 Parties.
The Vienna Convention emerged in response to mounting scientific evidence linking human activities, particularly the release of chlorofluorocarbons (CFCs) and other ozone-depleting substances (ODSs), to the deterioration of the stratospheric ozone layer. The ozone layer serves as a critical shield, absorbing harmful ultraviolet (UV) radiation from the sun. Its depletion posed severe risks, including increased incidences of skin cancer, cataracts, and disruptions to ecosystems. Recognizing these threats, the Vienna Convention established a framework for international cooperation, facilitating scientific research, data sharing, and policy coordination among nations.
The Vienna Convention’s significance lies in its non-binding nature, which fostered global consensus and paved the way for more stringent measures under the legally binding Montreal Protocol. Adopted in 1987 and entering into force in 1989, the Montreal Protocol set specific targets for the phase-out of ODSs. Its success can be attributed to its dynamic nature, allowing for amendments and adjustments in response to scientific advancements. The most notable of these amendments include the London (1990), Copenhagen (1992), Montreal (1997), and Kigali (2016) Amendments, which strengthened commitments by expanding the list of controlled substances and accelerating phase-out schedules. The Vienna Convention and the Montreal Protocol also played a crucial role in paving the way for the establishment of the Intergovernmental Panel on Climate Change (IPCC) in 1988. The success of the Montreal Protocol in curbing ODSs highlighted the effectiveness of science-based policy interventions, which became a guiding principle for the IPCC.
The Montreal Protocol is widely regarded as one of the most successful international treaties. The United Nations Environment Programme (UNEP) reports that, with continued compliance, the ozone layer is projected to recover to pre-1980 levels by the middle of the 21st century. Furthermore, the protocol has contributed to climate change mitigation, as many ODSs are also potent greenhouse gases.
... Given that current temperature trends prevail, that course of profound biogeographic transformation appears conceivable (Kullman & Öberg 2023a, b). However, history learns that climate and high-elevation tree communities perform hazardously and unpredictably (Hustich1978; Kullman 1991; Kuuluvainen et al. 2017;Vinós 2022), which urge for unprejudiced monitoring rather than presumptive and futuristic modelling. Just a few exceptionally cold years, with persistent and severe ground frost and late snow melt, may extirpate pine treeline populations built up over decades, of the kind presented in this paper (Mikola 1978;Kullman & Högberg 1989;Kullman 1991). ...
In a context of post-Little Ice Age (AD 1300-1900), climate warming and associated general progressive high-mountain landscape transformation, demographic changes in the pine (Pinus sylvestris) treeline ecotone were monitored over the years 1973-2024. The main focus was on a system of 18 permanent plots, randomly located within the pine treeline ecotone of the southern Swedish Scandes. Overall, unprecedented population growth (>300 %) was recorded, with a particularly high rate after the year of 2010, contingent on markedly increased seed viability, that significantly correlated with summer air temperature rise. The obtained changes are part of reponses to summer and winter regional climate warming and associated elevational treeline advance, encompassing the past 100 years or more. At a local scale, soil temperatures during the winter have increased over the past few decades, which has reduced the incidence of needle and shoot injuries and ensuing individual mortality, caused by winter desiccation and fine root dysfunction. Over the same period of time, winter precipitation (snow cover) has decreased. The latter circumstance implies earlier snow melt and a lowered risk of mechanical stress to young seedlings and saplings, as well as injuries by parasitic fungi. Another important aspect of decreased winter precipitation is that the growth period is prolonged, which may be a benefit to an evergreen species like Pinus sylvestris. The future evolution of the pine treeline ecotone is uncertain, given the unpredictable character of future climate change and its interactions with extant forest communities. Nevertheless, we may be currently witnesssing an embryonic new treeline ecotone under evolution, with pine as an increasingly important subalpine constituent.
... Carbon fluxes GtCO2/y References Stock -Flux Limestone rocks 140.000.000 +3.2 × 10 −5 (Sorokhtin et al., 2007) - (Vinos, 2022) Inorganic ocean 39.000 +10.3 (Friedlingstein et al., 2023) Limestone rocks are the main carbon reservoirs on the planet. Their formation and that of hydrocarbons were to the detriment of the atmosphere, which went from 7.000 to 420 ppmv in 600 million years (Godwin, 2022). ...
According to the quantities of plant and animal products placed on the world market in 2022, agriculture and forestry captured 20.1 ± 1.5 billion tonnes (Gt or Pg) of CO2, with a weighted mean duration of the corresponding storage of 10.9 ± 3.3 years. These figures are supplemented here by the unharvested above-ground and below-ground parts of plants that are left in place and increase the soil organic carbon pool. This brings the capture by cultivated whole plants to 41.0 ± 0.6 GtCO2, and the storage duration weighted mean to 26.3 ± 2.0 years in 2022. This was the largest global contribution to the reduction of atmospheric CO2 by amplitude and duration, which bio-remediated the global anthropogenic emissions totally, cancelling their influence on climate. The enrichment of the atmosphere with CO2 comes probably from the ocean, which could be a source and not a sink. Complementary approaches, freed from doctrinal preconceptions, should make it possible to clarify further the compensations of CO2 emissions by plants and their environmental consequences .
The impact of agriculture on the climate remains underestimated due to the systematic exclusion of annual crops from carbon budgets. Considered too ephemeral, these crops are nevertheless responsible for the absorption and storage of approximately one-third of the carbon biofixed by photosynthesis, with half-lives that are not limited to a single season but extend on average over 8.9 years. The kinetics of variation in carbon capture and release by cultivated plants over the half-century were simulated using two error functions which made it possible to complete the probabilistic calculation of the carbon balance components. In 2023, all cultivated plants-crops, grasslands, and forest plantations-had a stored carbon half-life of 17.6 years. They had removed 39.2 billion tonnes of CO₂/year from the atmosphere, more than global emissions from hydrocarbon combustion. Simulation of time distribution suggests that cultivated plants would have constituted a net stock of 124 billion tons of carbon by 2023, based on 455 billion tons of CO2 removed from the atmosphere, or 14% of its atmospheric mass. Given the importance of carbon capture and storage by cultivated plants, both in duration and quantity, rural activities should be integrated into carbon balances and the resulting climate strategies and recognized as a carbon capture and storage (CCS) device in carbon cycle regulation policies. This recognition would allow for the fair valuation of the work of farmers and foresters as part of the ecological transition, particularly through remuneration mechanisms such as carbon credits.
L'impact de l'agriculture sur le climat reste sous-estimé en raison de l'exclusion systématique des cultures annuelles dans les bilans carbone. Jugées trop éphémères, ces cultures sont pourtant responsables de l'absorption et du stockage d'environ un tiers du carbone biofixé par photosynthèse avec des demi-vies qui ne se limitent pas à une saison, mais s'étendent en moyenne sur 8,9 années. La cinétique de variation des captages et restitutions de carbone par les plantes cultivées sur le demi-siècle a été simulée à l'aide de deux fonctions d'erreur qui ont permis de compléter le calcul probabiliste des éléments du bilan carbone, et notamment des captages intermédiaires et des restitutions par minéralisation des biomasses produites. En 2023, la demi-vie du carbone stocké par l'ensemble des plantes cultivées-cultures, prairies et plantations forestières-était de 17,6 années. Les plantes cultivées avaient capté 39,2 GtCO₂/an, soit plus que les émissions mondiales par combustion d'hydrocarbures fossiles (37,8 GtCO₂/an). Le solde net de ces captages et restitutions était un puits de CO2 qui compensait 84% des émissions fossiles. Nos résultats suggèrent, à rebours de certaines évaluations précédentes, que les océans pourraient avoir un rôle moins dominant comme puits de carbone que généralement admis, voire constituer une source nette dans certaines conditions. La répartition dans le temps que permet cette simulation suggère que les plantes cultivées auraient constitué un stock net de 124 GtC à partir de 455 GtCO2 prélevés dans l'atmosphère, soit 14% de la masse atmosphérique. Devant l'importance du captage et stockage de carbone des plantes cultivées en durées comme en quantités, les activités rurales devraient être intégrées dans les bilans carbone et les politiques climatiques qui en résultent, et reconnues en tant que dispositif de captage et stockage de carbone (CSC) dans les mécanismes de régulation du cycle du carbone. Cette reconnaissance permettrait une valorisation équitable du travail des agriculteurs et forestiers dans le cadre de la transition écologique, notamment par des mécanismes de rémunération tels que les crédits carbone. L'exclusion des cultures annuelles semble reposer sur une logique comptable focalisée sur les stocks durables, ce qui peut conduire à une sous-estimation des flux réels de carbone associés à l'agriculture. Une telle approche pourrait freiner la pleine reconnaissance du rôle de l'agriculture dans l'atténuation climatique, en particulier dans les pays en développement qui dépendent fortement de cultures annuelles. Ces résultats suggèrent que les plantes cultivées pourraient jouer un rôle plus central dans les stratégies climatiques futures en intégrant les capacités de captage et de stockage de l'agriculture, de l'élevage et de la foresterie.
The impact of agriculture on the climate remains underestimated due to the systematic exclusion of annual crops from carbon balances. Considered too ephemeral, these crops are nevertheless responsible for the absorption and storage of approximately one-third of the carbon biofixed by photosynthesis, with half-lives that are not limited to a single season, but extend on average over 8.9 years. The kinetics of variation in carbon capture and release by cultivated plants over the half-century was simulated using two error functions that made it possible to complete the probabilistic calculation of the elements of the carbon balance, and in particular intermediate capture and release by mineralization of the biomass produced. In 2023, the half-life of carbon stored by all cultivated plants-crops, grasslands, and forest plantations-was 17.6 years. Cultivated plants captured 39.2 GtCO₂/year, more than global emissions from fossil fuel combustion (37.8 GtCO₂/year). The net result of these captures and releases was a CO2 sink that offset 84% of fossil fuel emissions. Another consequence of this reassessment is that the carbon budget reveals the role of the oceans as a source and not as a sink. The distribution over time allowed by this simulation suggests that cultivated plants would have constituted a net stock of 124 GtC from 455 GtCO2 taken from the atmosphere, or 14% of the atmospheric mass. Given the importance of carbon capture and storage by crops in terms of both duration and quantity, rural activities should be integrated into carbon balances and the resulting climate policies, and recognized as a carbon capture and storage (CCS) mechanism in carbon cycle regulation mechanisms. This recognition would allow for fair recognition of farmers' and foresters work as part of the ecological transition, particularly through remuneration mechanisms such as carbon credits. The exclusion of annual crops stems from a rigid accounting logic, focused on sustainable stocks to the detriment of actual carbon fluxes. This truncated vision hinders recognition of the fundamental role of agriculture in climate mitigation and raises misunderstandings in developing countries. It is time to place all cultivated plants, including annuals, at the heart of climate strategies based on up-to-date scientific data and integrating the capture and storage capacities of agriculture, livestock and forestry.
Hace aproximadamente cincuenta años, en los años 70 del siglo pasado, las élites capitalistas idearon un plan para imponer un gobierno supranacional. Este plan ha sido llamado de varias maneras a lo largo del tiempo: Nuevo Orden Mundial, Agenda 2030, y más recientemente Pacto para el Futuro. Bajo eufemismos edulcorados como los “Objetivos de Desarrollo Sostenible (ODS)” que nadie podría rebatir, escondieron los verdaderos objetivos del plan que no eran otros que la depopulación mundial y el sometimiento de la soberanía de las naciones a un despótico gobierno global. Parte de la estrategia consistió en prácticas terroristas simuladas, como el COVID19, o supuestos hechos científicos como el “Cambio Climático”. En este libro analizamos esos planes. Comentamos los diferentes ejes transversales del conocimiento que tocan, y cómo la evidencia científica ha sido tergiversada, manipulada y desprovista de toda veracidad.
D'après les quantités de produits végétaux et animaux mis sur le marché mondial en 2022, l'agriculture et la sylviculture ont capté 20,1±1,5 milliards de tonnes (Gt ou Pg) de CO2, avec une durée moyenne pondérée du stockage correspondant de 10,9±3,3 années. Ces chiffres sont complétés ici par ceux des parties non récoltées aériennes et souterraines de ces plantes qui sont laissées sur place et forment le pool de carbone organique du sol. Cela porte le captage par les plantes entières cultivées à 41,0±0,6 GtCO2, et la durée de stockage moyenne pondérée à 26,3±2,0 ans en 2022. Il s'agissait de la plus importante contribution planétaire à la réduction du CO2 atmosphérique par l'ampleur et la durée, qui compensait totalement les émissions anthropiques mondiales, ce qui annule leur influence sur le climat. L'enrichissement de l'atmosphère en CO2 provient probablement de l'océan qui serait une source et non un puits. Des approches complémentaires, libérées des préjugés doctrinaux, devraient permettre de préciser davantage les compensations des émissions de CO2 par les plantes et leurs conséquences environnementales. Abstract: According to the quantities of plant and animal products placed on the world market in 2022, agriculture and forestry captured 20. ±1.5 billion tonnes (Gt or Pg) of CO2, with a weighted mean duration of the corresponding storage of 10.9±3.3 years. These figures are supplemented here by the unharvested above-ground and below-ground parts of plants that are left in place and increase the soil organic carbon pool. This brings the capture by cultivated whole plants to 41.0±0.6 GtC2, and the storage duration weighted mean to 26.3±2.0 years in 2022. This was the largest global contribution to the reduction of atmospheric CO2 by amplitude and duration, which bio-remediated the global anthropogenic emissions totally, cancelling their influence on climate. The enrichment of the atmosphere with CO2 comes 2 probably from the ocean, which could be a source and not a sink. Complementary approaches, freed from doctrinal preconceptions, should make it possible to clarify further the compensations of CO2 emissions by plants and their environmental consequences.
Captage de carbone par les plantes entières et durée du stockage
Arnaud Muller-Feuga Baillargues, le 15 août 2024
Résumé : D'après les quantités de produits végétaux et animaux mis sur le marché en 2022, l'agriculture et la sylviculture ont capté 21,2±1,7 milliards de tonnes (Gt ou Pg) de CO2. La durée moyenne pondérée de ce captage et stockage par les plantes était de 9,8±2,5 années. Ces chiffres sont complétés ici par celui des parties non récoltées aériennes et souterraines des plantes qui sont laissées sur place et viennent grossir le pool de carbone organique du sol. Leur prise en compte porte le captage et le stockage par les plantes entières cultivées à 49,3±12,9 GtCO2 et la durée moyenne pondérée par les poids anhydres de stockage à 17±3,2 ans en 2022. Il s'agissait de la plus importante contribution planétaire à la réduction du CO2 atmosphérique qui compensait largement les émissions anthropiques mondiales. L'enrichissement de l'atmosphère en CO2 pourrait bien provenir de la seule source possible : l'océan.
Abstract: Based on the quantities of plant and animal products placed on the market in 2022, agriculture and forestry captured 21.2±1.7 billion tonnes (Gt or Pg) of CO2. The weighted average duration of this capture and storage by plants was 9.8±2.5 years. These figures are supplemented here by that of the unharvested above-ground and below-ground parts of plants that are left in place and increase the soil organic carbon pool. Taking them into account brings the capture and storage by cultivated whole plants to 49.3±12.9 GtCO2 in 2022 and the storage duration to 31±6.0 years. This was the largest global contribution to the reduction of atmospheric CO2 which bio remediated more than global anthropogenic emissions. The enrichment of the atmosphere with CO2 could well come from the only possible source: the ocean.
Mots clés: captage, stockage, carbone, CO2, agriculture, sylviculture, plantes entières océan, durée de stockage.
Prior to the mid‐19th century, Earth was in the grip of the Little Ice Age. Since then, temperatures have on average trended upward. At the same time, human emissions of carbon dioxide (CO 2 ) have increased, and the interest of scientists has turned to consider the extent of the relative contributions of anthropogenic CO 2 and natural forces to warming.
The IPCC Sixth Assessment Report (AR6) Working Group II (WGII) claims that human‐caused climate change or global warming is dangerous. According to the report, “Human‐induced climate change … has caused widespread adverse impacts and related losses and damages to nature and people, beyond natural climate variability. … The rise in weather and climate extremes has led to some irreversible impacts as natural and human systems are pushed beyond their ability to adapt ( high confidence )” (IPCC, 2022a, p. 9).
The AR6 WGI and WGII reports measure climate change as the global warming since 1750 or 1850. The period before these dates is commonly referred to as the “pre‐industrial period.” The Little Ice Age, a phrase rarely used in AR6, extends from about 1300 to 1850. It was a very cold and miserable time for humanity, with a lot of well documented extreme weather in the historical record from all over the Northern Hemisphere. It was also a time of frequent famines and pandemics. Arguably today's climate is better than then, not worse.
None‐the‐less, the IPCC claims that extreme weather events are worse now than in the past, however observations do not support this. Some extreme weather events, such as the land area under extreme drought (Lomborg, 2020), is decreasing, not increasing. Globally the incidence of hurricanes shows no significant trend (IPCC, 2013, p. 216; Lomborg, 2020).
Observations show no increase in damage or any danger to humanity today due to extreme weather or global warming (Crok & May, 2023, pp. 140–161; Scafetta, 2024). Climate change mitigation, according to AR6, means curtailing the use of fossil fuels, even though fossil fuels are still abundant and inexpensive. Since the current climate is arguably better than the pre‐industrial climate and we have observed no increase in extreme weather or climate mortality, we conclude that we can plan to adapt to any future changes. Until a danger is identified, there is no need to eliminate fossil fuel use.
The subalpine landscape between forest and alpine tundra has changed in important respects due the common climate amelioration, that peaked for the first time by the late 1930s. That point of time marks a fundamental break in the ecological recovery following the brutal nature and societal regression during the preceding Little Ice Age. Today, the new and warmer climate can be sensed as a greener, lusher and more species rich subalpine and alpine plant cover, where pine may become more dominant in the future. There is currently nothing to suggest that dystopic projections of a vanishing alpine world would come true. Development over the past 100 years is well within the frames of natural climate and ecosystem dynamics during the postglacial period. The living mountainscape is changing marginally in the new and slowly warming climate. Overall, an aesthetic, rich and inspiring landscape is likely to prevail. ZUSAMMENFASSUNG Die subalpine Landschaft zwischen Wald und alpiner Tundra hat sich durch die allgemeine Klimaverbesserung, die in den späten 1930er Jahren ihren ersten Höhepunkt erreichte, in wichtigen Punkten verändert. Dieser Zeitpunkt markiert eine grundlegende Zäsur in der ökologischen Entwicklung nach dem brutalen natürlichen und gesellschaftlichen Einschnitt während der vorangegangenen Kleinen Eiszeit. Heute macht sich das neue, wärmere Klima in einer grüneren, üppigeren und artenreicheren subalpinen und alpinen Pflanzendecke bemerkbar, in der die Kiefer in Zukunft dominanter werden könnte. Derzeit deutet nichts darauf hin, dass dystopische Projektionen einer verschwindenden alpinen Welt wahr werden. Die Entwicklung der letzten 100 Jahre liegt durchaus im Rahmen der natürlichen Klima
Radiative energy flux data, downloaded from CERES, are evaluated with respect to their variations from 2001 to 2020. We found the declining outgoing shortwave radiation to be the most important contributor for a positive TOA (top of the atmosphere) net flux of 0.8 W/m² in this time frame. We compare clear sky with cloudy areas and find that changes in the cloud structure should be the root cause for the shortwave trend. The radiative flux data are compared with ocean heat content data and analyzed in the context of a longer-term climate system enthalpy estimation going back to the year 1750. We also report differences in the trends for the Northern and Southern hemisphere. The radiative data indicate more variability in the North and higher stability in the South. The drop of cloudiness around the millennium by about 1.5% has certainly fostered the positive net radiative flux. The declining TOA SW (out) is the major heating cause (+1.42 W/m² from 2001 to 2020). It is almost compensated by the growing chilling TOA LW (out) (−1.1 W/m²). This leads together with a reduced incoming solar of −0.17 W/m² to a small growth of imbalance of 0.15 W/m². We further present surface flux data which support the strong influence of the cloud cover on the radiative budget.
Background
Exposure to cold or hot temperatures is associated with premature deaths. We aimed to evaluate the global, regional, and national mortality burden associated with non-optimal ambient temperatures.
Methods
In this modelling study, we collected time-series data on mortality and ambient temperatures from 750 locations in 43 countries and five meta-predictors at a grid size of 0·5° × 0·5° across the globe. A three-stage analysis strategy was used. First, the temperature–mortality association was fitted for each location by use of a time-series regression. Second, a multivariate meta-regression model was built between location-specific estimates and meta-predictors. Finally, the grid-specific temperature–mortality association between 2000 and 2019 was predicted by use of the fitted meta-regression and the grid-specific meta-predictors. Excess deaths due to non-optimal temperatures, the ratio between annual excess deaths and all deaths of a year (the excess death ratio), and the death rate per 100 000 residents were then calculated for each grid across the world. Grids were divided according to regional groupings of the UN Statistics Division.
Findings
Globally, 5 083 173 deaths (95% empirical CI [eCI] 4 087 967–5 965 520) were associated with non-optimal temperatures per year, accounting for 9·43% (95% eCI 7·58–11·07) of all deaths (8·52% [6·19–10·47] were cold-related and 0·91% [0·56–1·36] were heat-related). There were 74 temperature-related excess deaths per 100 000 residents (95% eCI 60–87). The mortality burden varied geographically. Of all excess deaths, 2 617 322 (51·49%) occurred in Asia. Eastern Europe had the highest heat-related excess death rate and Sub-Saharan Africa had the highest cold-related excess death rate. From 2000–03 to 2016–19, the global cold-related excess death ratio changed by −0·51 percentage points (95% eCI −0·61 to −0·42) and the global heat-related excess death ratio increased by 0·21 percentage points (0·13–0·31), leading to a net reduction in the overall ratio. The largest decline in overall excess death ratio occurred in South-eastern Asia, whereas excess death ratio fluctuated in Southern Asia and Europe.
Interpretation
Non-optimal temperatures are associated with a substantial mortality burden, which varies spatiotemporally. Our findings will benefit international, national, and local communities in developing preparedness and prevention strategies to reduce weather-related impacts immediately and under climate change scenarios.
Atmospheric meridional energy transport into the Arctic plays an important role in Arctic weather and climate. The transport of latent energy in the form of water vapour strongly influences the Arctic atmosphere. The transport is achieved by circulation mechanisms on various scales and is largely comprised of extreme transport events. Here, we use a Fourier‐based method of dividing the latent energy transport into spatial scales and investigate the extent to which extreme events in latent energy transport on planetary and synoptic scales have changed over the past four decades, and how they influence the Arctic winter temperatures. We find that wintertime extreme transport events on planetary scales are associated with warm temperature anomalies across the entire Arctic, while the extreme events on synoptic scales have less impact on the Arctic temperatures. We show that over the past four decades, there has been a significant increase in the wintertime latent energy transport by planetary‐scale systems, and a decrease in synoptic‐scale transport. This shift may have contributed to the amplified warming observed in the Arctic winter over the past decades.
Five years after the adoption of the Paris Climate Agreement, growth in global CO2 emissions has begun to falter. The pervasive disruptions from the COVID-19 pandemic have radically altered the trajectory of global CO2 emissions. Contradictory effects of the post-COVID-19 investments in fossil fuel-based infrastructure and the recent strengthening of climate targets must be addressed with new policy choices to sustain a decline in global emissions in the post-COVID-19 era. Growth in CO2 emissions has slowed since the Paris Agreement 5 years ago. The COVID-19 pandemic has caused a drop in emissions of about 7% in 2020 relative to 2019, but strong policy is needed to address underlying drivers and to sustain a decline in global emissions beyond the current crisis.
The teleconnection between the Quasi‐Biennial Oscillation (QBO) and the boreal winter polar vortex, the Holton–Tan effect, is analyzed in the Whole Atmosphere Community Climate Model (WACCM) with a focus on how stationary wave propagation varies by QBO phase. These signals are difficult to isolate in reanalyses because of large internal variability in short observational records, especially when decomposing the data by QBO phase. A 1,500‐year ensemble is leveraged by defining the QBO index at five different isobars between 10 and 70 hPa. The Holton–Tan effect is a robust part of the atmospheric response to the QBO in WACCM with warming of the polar stratosphere during easterly QBO (QBOE). A nudging technique is used to reduce polar stratospheric variability in one simulation. This enables isolation of the impact of the QBO on the atmosphere in the absence of a polar stratospheric response to the QBO: referred to as the “direct effect” and the polar stratospheric response, “indirect effect.” This simulation reveals that the polar stratospheric warming during QBOE pushes the tropospheric jet equatorward, opposing the poleward shift of the jet by the QBOE, especially over the North Pacific. The Holton–Tan effect varies over longitude. The QBO induces stronger planetary wave forcing to the mean flow in the extratropical lower stratosphere between Indonesia and Alaska. The North Pacific polar stratosphere responds to this before other longitudes. What follows is a shift in the position of the polar vortex toward Eurasia (North America) during easterly (westerly) QBO. This initiates downstream planetary wave responses over North America, the North Atlantic, and Siberia. This spatiotemporal evolution is found in transient simulations in which QBO nudging is “switched on.” The North Pacific lower stratosphere seems more intrinsically linked to the QBO while other longitudes appear more dependent on the mutual interaction between the QBO and polar stratosphere.
Even though meteorologists have been aware of atmospheric blocking for more than 100 years, it is a phenomenon still not well forecast or completely understood. Also, while there is not one standard accepted definition, there are some commonalities known about the understanding of blocking behavior. Blocking occurs less often than other destructive phenomena, but globally their occurrence has increased since the beginning of the century. The longevity of blocking means it can negatively impact agricultural and economic activity and human comfort by bringing extreme conditions not only to the areas where they occur but also to locations well upstream and downstream. Additionally, while it is known where blocking occurs and their general character has been well described, operational models still struggle to replicate the intensity and duration even though improvement has been noted in the timing and location of onset. Climatologically, models still underestimate their occurrence. In the last 40 years, investigators have used case study analysis and numerical and theoretical models to understand the onset and maintenance of blocking. Comparatively few have examined block decay. This review endeavors to cover the highlights of the history of blocking investigations, especially in the last few decades, in order to provide an understanding for a more general scientific audience.
Eight proxy records of Northern Fennoscandian summer temperature variability were analyzed for the AD 1700–2000 period. Stable and statistically significant correlation between the summer temperature reconstructions and a quasi 22-year Hale solar cycle was found to be present through the entire study period. The revealed solar–climatic link is a result of the effect of a weak solar cycle signal on a climatic system having internal bi-decadal variability. Precise physical mechanisms to explain this link are far from clear but galactic cosmic ray flux appears a probable physical agent to mediate the solar effect to the lower troposphere. No evidence of a link between Northern Fennoscandian temperature and quasi 20-year planetary-tidal cycle was found.
For the current generation of earth system models participating in the Coupled Model Intercomparison Project Phase 6 (CMIP6), the range of equilibrium climate sensitivity (ECS, a hypothetical value of global warming at equilibrium for a doubling of CO 2 ) is 1.8°C to 5.6°C, the largest of any generation of models dating to the 1990s. Meanwhile, the range of transient climate response (TCR, the surface temperature warming around the time of CO 2 doubling in a 1% per year CO 2 increase simulation) for the CMIP6 models of 1.7°C (1.3°C to 3.0°C) is only slightly larger than for the CMIP3 and CMIP5 models. Here we review and synthesize the latest developments in ECS and TCR values in CMIP, compile possible reasons for the current values as supplied by the modeling groups, and highlight future directions. Cloud feedbacks and cloud-aerosol interactions are the most likely contributors to the high values and increased range of ECS in CMIP6.
Along with the amplified warming and dramatic sea ice decline, the Arctic has experienced regionally and seasonally variable moistening of the atmosphere. Based on reanalysis data, this study demonstrates that the regional moistening patterns during the last four decades, 1979– 2018, were predominantly shaped by the strong trends in horizontal moisture transport. Our results suggest that the trends in moisture transport were largely driven by changes in atmospheric circulation. Trends in evaporation in the Arctic had a smaller role in shaping the moistening patterns. Both horizontal moisture transport and local evaporation have been affected by the diminishing sea ice cover during the cold seasons from autumn to spring. Increases in evaporation have been restricted to the vicinity of the sea ice margin over a limited period during the local sea ice decline. For the first time we demonstrate that, after the sea ice has disappeared from a region, evaporation over the open sea has had negative trends due to the effect of horizontal moisture transport to suppress evaporation. Near the sea ice margin, the trends in moisture transport and evaporation and the cloud response to those have been circulation dependent. The future moisture and cloud distributions in the Arctic are expected to respond to changes in atmospheric pressure patterns; circulation and moisture transport will also control where and when efficient surface evaporation can occur.