Warming in the Arctic appears to be exerting an influence on extreme cold winter weather in some parts of the world, according to a new study published online Wednesday in the journal Nature Climate Change.
The study, conducted by an international team of researchers, found that the cause of recent severe cold winters in places such as the eastern part of the United States and Britain, could be traced back to natural changes to the jet stream’s position, which was intensified by the warming in the Arctic.
The jet stream consists of ribbons of very strong winds which move weather systems around the globe. Jet streams are found nine to 16 km above the surface of the Earth.
The position of a jet stream varies within the natural fluctuations of the environment. They are caused by the temperature difference between tropical air masses and polar air masses.
Previous studies have shown that more episodes of severe cold weather will plunge from the Arctic into the mid-latitudes, as the jet stream gets wavy.
“We’ve always had years with wavy and not so wavy jet stream winds, but in the last one to two decades the warming Arctic could well have been amplifying the effects of the wavy patterns,” said Professor Edward Hanna at University of Sheffield, in a press release from the university. Hanna is one of the authors of the study.
“This may have contributed to some recent extreme cold winter spells along the eastern seaboard of the United States, in eastern Asia, and at times over the UK,” Hanna said.
Professor Hanna also noted that improving the ability to predict how climate change is affecting the jet stream will help to improve the long-term prediction of winter weather in some of the most highly populated regions of the world.
Global warming and climate change are terms for the observed century-scale rise in the average temperature of the Earth’s climate system and its related effects. Multiple lines of scientific evidence show that the climate system is warming. Although the increase of near-surface atmospheric temperature is the measure of global warming often reported in the popular press, most of the additional energy stored in the climate system since 1970 has gone into the oceans. The rest has melted ice and warmed the continents and atmosphere. Many of the observed changes since the 1950s are unprecedented over tens to thousands of years.
Scientific understanding of global warming is increasing. The United Nations Intergovernmental Panel on Climate Change (IPCC) reported in 2014, that “It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.” Human activities have led to carbon dioxide concentrations above levels not seen in hundreds of thousands of years. Currently, about half of the carbon dioxide released from the burning of fossil fuels remains in the atmosphere. The rest is absorbed by vegetation and the oceans. Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to 1.7 °C (0.5 to 3.1 °F) for their lowest emissions scenario and 2.6 to 4.8 °C (4.7 to 8.6 °F) for the highest emissions scenario. These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing.
Future climate change and associated impacts will differ from region to region around the globe. Anticipated effects include warming global temperature, rising sea levels, changing precipitation, and expansion of deserts in the subtropics. Warming is expected to be greater over land than over the oceans and greatest in the Arctic, with the continuing retreat of glaciers, permafrost and sea ice. Other likely changes include more frequent extreme weather events including heat waves, droughts, heavy rainfall with floods and heavy snowfall; ocean acidification; and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels. Because the climate system has a large “inertia” and greenhouse gases will stay in the atmosphere for a long time, many of these effects will not only exist for decades or centuries, but will persist for tens of thousands of years.
Possible societal responses to global warming include mitigation by emissions reduction, adaptation to its effects, building systems resilient to its effects, and possible future climate engineering. Most countries are parties to the United Nations Framework Convention on Climate Change (UNFCCC), whose ultimate objective is to prevent dangerous anthropogenic climate change. Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 °C (3.6 °F) relative to pre-industrial levels, with efforts made to limit warming to 1.5 °C (2.7 °F).
Public reactions to global warming and concern about its effects are also increasing. A global 2015 Pew Research Center report showed a median of 54% consider it “a very serious problem”. There are significant regional differences, with Americans and Chinese (whose economies are responsible for the greatest annual CO2emissions) among the least concerned.