Showing results for: Climate trends/projections
This explainer from Carbon Brief outlines nine interlinked “tipping points” where climate warming could trigger an abrupt change. They include disintegration of ice sheets, changes in ocean circulation, thawing of permafrost, and dieback of ecosystems such as the Amazon rainforest and coral reefs.
According to the Global Risks Report 2020 by the global NGO World Economic Forum, the five risks with the greatest likelihood of happening all relate to the environment (as opposed to the economy, society, geopolitics or technology). The five risks are: extreme weather, climate action failure, natural disasters, biodiversity loss and human-made environmental disasters.
This commentary reviews the evidence on climate tipping points - i.e. irreversible (on a human timescale) and abrupt shifts from one climate state to another - and concludes that several interlinked tipping points could be already active or very near to being triggered. Cutting emissions could still slow down the rate at which the tipping points operate, the authors argue.
In this blog post, Asaf Tzachor of the Centre for the Study of Existential Risk at the University of Cambridge describes four pathways by which the global food system could collapse. He calls for greater awareness that interactions between different processes (such as ocean acidification, climate change, wildfires and plant diseases) could lead to vicious cycles, and argues that policymakers should seek leverage points in the food system.
This paper models the changes in vegetation and agricultural land use that might be expected if action is not taken to mitigate climate change. Temperatures in the UK would increase by around 5.4°C in the growing season and 4.7°C out of the growing season by the end of the century. The growing season would become drier by around 37% and the non-growing season would become 7% wetter, with drying being less pronounced in the north of the UK than the rest of the country.
The Intergovernmental Panel on Climate Change (IPCC) has published a special report reviewing the impacts of climate change on the oceans and cryosphere (ice gaps, glaciers and frozen ground), incorporating evidence that has been published since the IPCC’s Fifth Assessment Report and Special Report on Global Warming of 1.5°C. It finds that climate change has shrunk ice sheets, glaciers and sea ice as well as heated permafrost (ground that normally remains frozen all year).
This paper finds that production of the top ten global crops has already been affected by climate change, with mixed impacts across both crop type and geographical area. Oil palm has seen a 13% decrease in yields relative to those that would have been seen under historical climate conditions, while soybean has seen a 4% increase.
This book, edited by Mirza Hasanuzzaman, Kamrun Nahar and Mohammad Amzad Hossain, provides a comprehensive overview of the response of wheat cultivation to changing environmental conditions, including extreme temperatures, drought and ultra-violet radiation.
Extreme climate events such as droughts and heat waves are better predictors of yield anomalies than indicators of climate averages in maize, rice and soybeans, according to this paper. Irrigation can mitigate the negative yield impacts of frequent warm days.
This paper uses climate models to estimate that average precipitation across many crop production areas will change by more than natural variability throughout the 21st century. Changes are seen even if emissions are relatively low, but meeting the Paris climate goals could reduce the extent of cropland that is affected.
This paper retrospectively models the impacts of ocean warming on the productivity of 235 fish populations around the world representing around one third of reported global catch. It uses a temperature-dependent population model to estimate that the overall maximum sustainable yield of the fish populations dropped by 4.1% between 1930 and 2010.
This paper models the impacts that the Paris Agreement on climate change would have on seafood production. It finds that three quarters of maritime countries would benefit from the Agreement’s implementation.
This report from The Lancet Commission identifies the drivers behind what it terms ‘The Global Syndemic’, i.e. co-occurring pandemics, of obesity, undernutrition and climate change. The report finds that no country has successfully reversed its epidemic of obesity because the underlying causes have not been solved.
The US Global Change Research Programme has published the second volume of its Fourth National Climate Assessment, which examines the human welfare, societal, and environmental impacts of climate change and variability across many sectors, including agriculture.
Losses of wheat, rice and maize to insects could increase by 10 to 25% per degree Celsius of climate warming, according to this paper. This is due to two main factors: insects have faster metabolisms at higher temperatures and therefore need to eat more; and insect population growth rates will also change with temperature.
The Intergovernmental Panel on Climate Change (IPCC) has released a special report on keeping climate change to 1.5°C. The report says, “Limiting global warming to 1.5°C would require rapid, far-reaching and unprecedented changes in all aspects of society.”