Research articles

N₂O emissions from rivers have increased globally by a factor of four between 1900 and 2016, with emissions starting to decline since the early 2000s. Most riverine N₂O emissions come from smaller streams, driven primarily by the use of nitrogen fertilizers in agriculture.

Climate change and habitat loss threaten species survival in Madagascar. Ruffed lemurs, a representative species in the eastern rainforest, could lose 38–93% of their habitat from climate change and deforestation by 2070; protecting areas from deforestation is necessary to protect Malagasy biodiversity.

It has been assumed that spatial patterns of warming are the same under transient and equilibrium scenarios. Analysis of a multi-model ensemble shows that this is not the case, with greater land warming for a transient state, increasing risks that need to be considered in adaptation planning.

Climate change affects the timing of bird migration, which can lead to mismatch with resource availability. Migration occurred earlier in spring and autumn in the United States during the past 24 years; warming led to later arrival in the western Unites States and earlier arrival in the rest of the country.

The Pacific Decadal Oscillation (PDO), a natural climate cycle, alters global climate and influences ecosystems as it varies between positive and negative phases. PDO predictability is reduced under warming as intensified ocean stratification shortens its lifespan and curtails its amplitude.

The risk of concurrent climate extremes affecting breadbasket regions is increasing with climate change, with wheat, maize and soybean crops at risk of simultaneous failure. Correlation between the regions and climate extremes should be considered to ensure food security in the future.

GHG emissions in sub-Saharan African countries are comparatively low, but continued economic and population growth could transform the region into a major emitter. Here, it is shown that the transportation sector has driven emissions in the past few decades, but new coal investments are likely to be a major driver in the near future.

Extreme weather events may raise public awareness of climate change. This comparative-case analysis shows that single events had limited impact on climate change discussion, but this was more common in Democratic communities and for weather events with a more certain attribution to climate change.

A large-scale meandering in the jet stream can cause simultaneous heat extremes in distant regions. When Rossby waves with wavenumbers 5 and 7 dominate circulation, there is an increased risk of heat extremes across major food-producing regions, raising the potential of multiple crop failures.

Hot weather can cause early childbirth, meaning shorter gestation. Daily US birth-rate data from 1969 to 1988 show that deliveries increased on hot days and that those births occurred up to two weeks early. Around 25,000 infants were born early each year, representing over 150,000 gestational days lost annually.

Terrestrial primary productivity will increase with CO₂ fertilization, but water limitation will decrease this positive effect. Analyses of Earth system model projections show that extreme droughts will have a much stronger impact on future productivity than mild and moderate droughts.

Qualitative comparative analysis of 25 case studies across climate change hotspots in Africa and Asia shows that male migration and women’s poor working conditions combine with either institutional failure or poverty to constrain women’s agency, which limits their adaptive capacity.

The ways in which ocean communities respond to warming are related to their composition. The variety of thermal affinities and thermal ranges of individual species, along with vertical temperature gradients, shape community response and allow the prediction of regional responses to warming.

Increased hybridization has the potential to threaten species diversity. Here population genetic computer simulations show that climate-induced adaptive introgression could readily lead to hybridization even when reproductive isolation is independent from climate.

Opinions on climate policy in the United States are politically polarized. Here, survey research shows that opinion polarization on the Green New Deal developed rapidly due to decreasing support among Republicans, which was associated with exposure to conservative media and increasing familiarity with the policy.

Wind speeds have reduced globally over land since the 1980s. In situ data show that this reversed around 2010, with natural ocean–atmosphere variability thought to drive the wind speed changes, as well as a 17% increase in potential wind energy for 2010–2017 and a boosted wind power capacity factor.

Estimates of N₂O emissions are important given its role as a GHG. Atmospheric inversions indicate emissions increased over the past decade at a rate 2.5 times that estimated using the IPCC default method, and the emissions response to N-input is larger than linear when N-input is high.

In the US, 99.8% of the 459 endangered animals are susceptible to at least one climate change sensitivity factor. Yet analysis of official documents (1973–2018) shows this risk does not translate into action: only 64% of species are considered threatened by climate change, and management planned for 18%.