Volume 9 Issue 10, October 2019

In recent years, the tropical Indian Ocean has experienced persistent warming larger than any other basin. Now research suggests that this may exert a stabilizing effect on the meridional overturning circulation in the north Atlantic Ocean by attenuating its recent weakening, with implications for climate change worldwide.

Within a single species, different populations can show strikingly varied responses to climate – often attributed to genetic differences of geographically separated populations. Now an elegant analysis, weaving together modelling with large-scale empirical data, demonstrates that ecoregion explains spatial variation in climate responses of the American pika.

Climate change is expected to severely impact farming in sub-Saharan Africa. Now research shows that crop wild relatives might be able to secure Africa’s existing cropping practices by providing the genetic diversity needed to adapt crops to climates that they have never seen before.

Understanding which factors influence future economic impacts from climate change is important for informing mitigation and adaptation strategies. This study demonstrates that projected economic impacts are primarily attributed to variation in socioeconomic development and future emissions trajectories, rather than uncertainties in the climate response.

The supply of dense Antarctic Bottom Water to the Atlantic overturning circulation has declined in recent years. Observations show that since 2014 this has stabilized and slightly recovered due to variability in upstream dense waters, with implications for the global climate.

The Indian Ocean is warming at an accelerated rate, and modelling experiments show teleconnections affecting the Atlantic meridional overturning circulation (AMOC). In a warming climate, reduced tropical Atlantic rainfall causes salinity changes strengthening the AMOC, while other factors weaken it.

Bananas are a staple food crop and important agricultural export for many countries. Here, it is shown that global banana yields have increased historically and will continue to increase in Africa but reduced yields are expected among the larger producers.

Future climate conditions threaten crops in sub-Saharan Africa. It is shown that most major sub-Saharan African crops have wild relatives that occur in regions better suited for future climate conditions, suggesting an opportunity for adaptation that does not require the adoption of new production systems.

A 30-year dataset shows that marsh plants increased primary productivity and stem density with CO₂ enrichment, but diameter and height decreased under nitrogen limitation. The addition of nitrogen reversed these changes, which is important to allow marshes to keep pace with rising sea levels.

Solar geoengineering could limit temperature increase, but its use is controversial. This study shows that climate experts are more opposed to geoengineering if they expect severe global climate change damages, but are more supportive if they expect severe damages in their home country.

Whether citizens are able to reject false information about climate change may depend on their confidence in their existing knowledge. This study shows that German citizens are less confident in their climate change knowledge than they should be based on their actual knowledge.

Diatoms have silicate skeletons that affect their buoyancy in the ocean. Ocean acidification reduces silicification, with varying effects between species, and could alter the marine carbon and silica cycles through changes in community composition and sinking rates.

Intraspecies response to climate change is expected to align with genetic affinity. Using the American pika as a case study suggests that divisions of species distributions best explain intraspecific heterogeneity in climate relationships.