Warm Spells in Arctic Stunt Crop Yields Across US, Study Suggests

Unusually warm periods in the Arctic stunt vegetation growth and crop yields across North America, a new study suggests.

The study is a new angle on the relatively recent area of research connecting rapid warming in the Arctic with the weather of mid-latitude regions.

Reduced plant and crop growth is down to two factors, the researchers say:  severe cold in northern North America and dry conditions in south-central US.  These are both linked to very warm spring temperatures in the Arctic, the study says.

But while the study adds to the weight of evidence that there is a connection between a warm Arctic and mid-latitude weather, it doesn’t tackle the “critical question” of whether one causes the other, another scientist tells Carbon Brief.

Arctic amplification
Temperatures in the Arctic are increasing around three times as fast as the global average – a phenomenon known as Arctic amplification.  One of the main reasons is the loss of sea ice in the region.  As the extent of the sea ice declines, energy from the sun that would have been reflected away is instead absorbed by the ocean.

In addition to the direct impacts of rapid Arctic warming – most notably the loss of sea ice – scientists also think that it could be having an indirect effect on weather patterns in the mid-latitude regions of the northern hemisphere.

This relatively recent – and sometimes controversial – area of research has linked a warming Arctic with very cold winters in the UK, North America and Central Asia, as well as longer-lasting summer heatwaves in Russia.

The new study, published in Nature Geoscience, takes the theory a step further – not only linking a warm Arctic to unusual weather patterns in North America, but also to the impacts on plant growth and crop yields.

Read more at Warm Spells in Arctic Stunt Crop Yields Across US, Study Suggests