In just a few decades, we are likely to see many fewer species on the planet than we see today. That is the grim message in a May 7, 2019, report from the United Nations on the status of species in this era of rapid climate change and human interventions in the environment. There now are as many as 1 million species threatened with extinction -- an unprecedented and accelerating die-off that cannot be prevented without transformative changes in our treatment of nature. The warnings come from the United Nations Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services. Its report is the product of 145 expert authors from 50 nations along with contributions from another 310 contributing authors. It is based on a review of 15,000 science and government sources. The human interventions include a tenfold increase in plastic pollution over the last 20 years; 400 million tons of heavy metals, toxic sludges and fertilizer pouring into global waters annually; a doubling of greenhouse gas pollution since 1980; the loss of 85% of the world's wetlands during the industrial era;
Antarctica has lost 4.76 trillion metric tons of ice in the last four decades, according to a study published by the Proceedings of the National Academy of Sciences. The process is expected to accelerate, causing more rapid sea level rise. But that's not the only consequence. The melting will dramatically affect the web of life in that region, as shown in the amazing new Netflix series "Our Planet".
The physical signs and socio-economic impacts of climate change are accelerating as record greenhouse gas concentrations drive global temperatures towards increasingly dangerous levels, according to a new report from the World Meteorological Organization. The WMO Statement on the State of the Global Climate in 2018, its 25th anniversary edition, highlights record sea level rise, as well as exceptionally high land and ocean temperatures over the past four years. This warming trend has lasted since the start of this century and is expected to continue. “The data released in this report give cause for great concern. The past four years were the warmest on record, with the global average surface temperature in 2018 approximately 1°C above the pre-industrial baseline,” notes UN Secretary General António Guterres. “These data confirm the urgency of climate action. This was also emphasized by the recent Intergovernmental Panel on Climate Change (IPCC) special report on the impacts of global warming of 1.5°C. The IPCC found that limiting global warming to 1.5°C will require rapid and far reaching transitions in land, energy, industry, buildings, transport and cities and
James Hansen et.al. in Atmospheric Chemistry and Physics. Modeling, paleoclimate evidence, and ongoing observations together imply that 2oC global warming above pre industrial level could produce several several changes in ocean overturning circulation, increasingly powerful storms, the potential for cooling in Europe and nonlinear sea-level rise.
Proceedings of the National Academy of Sciences of the United States of America Aug. 14, 2018 Excerpts from "Trajectories of the Earth System in the Anthropocene" Will Steffen, Johan Rockström, Katherine Richardson, Timothy M. Lenton, Carl Folke, Diana Liverman, Colin P. Summerhayes, Anthony D. Barnosky, Sarah E. Cornell, Michel Crucifix, Jonathan F. Donges, Ingo Fetzer, Steven J. Lade, Marten Scheffer, Ricarda Winkelmann, and Hans Joachim Schellnhuber PNAS August 14, 2018 115 (33) 8252-8259; published ahead of print August 6, 2018 https://doi.org/10.1073/pnas.1810141115 Edited by William C. Clark, Harvard University, Cambridge, MA, and approved July 6, 2018 (received for review June 19, 2018) Abstract We explore the risk that self-reinforcing feedbacks could push the Earth System toward a planetary threshold that, if crossed, could prevent stabilization of the climate at intermediate temperature rises and cause continued warming on a “Hothouse Earth” pathway even as human emissions are reduced. Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene. We examine the evidence that such a threshold might exist and where it might be. If the threshold is crossed, the
Self-reinforcing feedbacks could push the Earth past the threshold of climate stabilization and into an ongoing path to a "Hothouse Earth", even if emissions were reduced. That is the conclusion of an international group of 16 scientists published Aug. 6, 2018, in the Proceedings of the National Academy of Science. "Crossing the threshold would lead to a much higher global average temperature than any interglacial in the past 1.2 million years and to sea levels significantly higher than at any time in the Holocene," the authors report. "We examine the evidence that such a threshold might exist and where it might be. "If the threshold is crossed, the resulting trajectory would likely cause serious disruptions to ecosystems, society, and economies. Collective human action is required to steer the Earth System away from a potential threshold and stabilize it in a habitable interglacial-like state. Such action entails stewardship of the entire Earth System—biosphere, climate, and societies—and could include decarbonization of the global economy, enhancement of biosphere carbon sinks, behavioral changes, technological innovations, new governance arrangements, and transformed social values." See the complete study
In order to keep global warming below 2oC, two-thirds of the world's proved fossil energy reserves will have to remain unburned. Nevertheless, oil, gas and coal companies are continuing to invest in exploration and are underestimating the risk of large stranded investments. In this seminal study, Carbon Tracker describes the "carbon bubble" and what it means for shareholders in fossil energy companies. Read more
Climate change is a significant threat to the health of the American people. The impacts of human-induced climate change are increasing nationwide. The overall findings of this study, conducted by a consortium of federal agencies, underscore the significance of the growing risk climate change poses to human health in the United States. Learn more
Ice melt, sea level rise and superstorms: evidence from paleoclimate data, climate modeling, and modern observations that 2 ◦C global warming could be dangerous
In 1988, James Hansen because the first climate scientists to warn Congress about global warming. Now he has issued a new study in which he concludes that climate change is more severe than we think. Read full article here: Ice melt, sea level rise and superstorms
February 2015 - by Alastair Brown - via Nature Climate Change Uncertainty about the spatial distribution of future climatic changes is dominated by differences in projections that result from climate model differences. Much of the model variance can be attributed to the representation of climate feedbacks that alter radiative flux by reinforcing, or attenuating, external climate forcing.… Read more here: Regional climate prediction
January 2015 - by Jennifer A Francis and Stephen J Vavrus - via IOP Science Abstract New metrics and evidence are presented that support a linkage between rapid Arctic warming, relative to Northern hemisphere mid-latitudes, and more frequent high-amplitude (wavy) jet-stream configurations that favor persistent weather patterns. We find robust relationships among seasonal and regional patterns of weaker poleward thickness gradients, weaker zonal upper-level winds, and a more meridional flow direction. These results suggest that as the Arctic continues to warm faster than elsewhere in response to rising greenhouse-gas concentrations, the frequency of extreme weather events caused by persistent jet-stream patterns will increase. Read full article here: Evidence for a wavier jet stream in response to rapid Arctic warming
October 2015 - via Nature Journal Some corals seem to be resilient to ocean acidification. As carbon dioxide emissions rise, ocean waters are absorbing more of the gas and becoming less alkaline, threatening the ability of corals and other marine organisms to make skeletons and shells. Lucy Georgiou at the University of Western Australia in Perth and… Read more: Corals cope with pH-altered waters