News & Views in 2020

International efforts to expand access to safely managed sanitation provide an opportunity to introduce new models for sanitation infrastructure with lower environmental impacts than existing systems. Now, measurements in Haiti show that composting of human waste reduces GHG emissions compared to existing methods.

The influence of the changing climate on individual snowstorms has been uncertain, in part due to the use of coarse model simulations. Now, research employing more detailed simulations finds fewer and smaller snowstorms as a result of warming, with a reduction in the amount and extent of extreme snowfall.

Climate migration involves complex interactions of environmental, social, political and economic factors. New research suggests that although wealthy global citizens try to prevent climate migration, they are willing to shoulder a greater share of the climate mitigation burden when extreme climate events hit poor countries.

Antarctic krill play a key role in Southern Ocean food webs but are vulnerable to climate change, with habitat shifts predicted in response. Now, a study of climate change impacts on a krill-specialist predator — the crabeater seal — suggests that this abundant marine mammal may be forced southwards with its prey.

Snow in the mountains provides a natural reservoir, storing water in the cold season for use later in the year. Now research demonstrates that reduced mountain snowpack due to rising temperatures makes drought harder to predict and jeopardizes irrigated agriculture throughout the world.

Policy makers debate whether responding to climate change can be complementary to economic growth. New research tracking competing economic ideas across the environmental debate shows that climate change is increasingly seen as an opportunity; however, many still argue that growth and climate action are in conflict.

Since 1980, European nations have made a tremendous effort to mitigate ozone pollution by reducing emissions, only to achieve limited success. Research now shows that vegetation stressed by heat and drought conditions has partly thwarted these actions.

Future Arctic methane emissions depend partly on interactions between soil carbon released during permafrost thaw and microbial physiology. Now, a model shows potential increased methane produced from thawing permafrost carbon could be offset by increased consumption by upland methanotrophs.

The partisan divide between Republicans and Democrats on climate change is large and shows no signs of narrowing. However, a new analysis shows that Republicans’ climate change attitudes were relatively unstable between 2014–2018, triggering cautious optimism that a tipping point in attitudes might be around the corner.

Under climate change, sea-level rise is expected to bring about large changes in the world’s coastlines. Now, research predicting future shoreline change from satellite data indicates loss of nearly 50% of sandy beaches by the end of the century.

Temperature affects the metabolic rates of species, their feeding interactions and their ability to persist in a given environment. Now research suggests that different effects of temperature on consumers and resources could cause food webs in cold climates to become less vulnerable to species loss, whereas tropical communities may be more vulnerable as temperatures climb.

Atmospheric aerosols have probably masked a significant portion of the greenhouse-gas-induced warming so far. Research now shows that this also may have masked some of the world’s increasing economic inequality.

Ground-level ozone is an air pollutant that is harmful to human health, as well as to plants, trees and crops. New analyses based on Earth system modelling show that reducing ozone from the energy, industrial and transportation sectors could mitigate climate change by enhancing the ability of vegetation to remove carbon dioxide from the atmosphere through photosynthesis.

The impacts of climate change on the ecohydrology of forested mountain regions are uncertain. New high-resolution modelling suggests that during a hot, dry summer in the Alps, stressed vegetation capitalizes on downslope water subsidies, amplifying runoff deficits and further depleting water resources.

For years, halogens have been known as destroyers of ‘good’ ozone, which acts as an upper-atmosphere shield from harmful ultraviolet radiation. Research now shows that natural halogen compounds emitted from the ocean help to control ‘bad’ ozone pollution at ground level and may continue to do so at a similar rate in future climate.

An anthropogenic fingerprint has been detected in long-term climate trends, but distinguishing human-induced change from natural variability in day-to-day weather remains a challenge. Research now finds that a human influence is discernible in global patterns of daily temperature and moisture.