The urgency of Arctic change - ScienceDirect

This article provides a synthesis of the latest observational trends and projections for the future of the Arctic. First, the Arctic is already changing rapidly as a result of climate change. Contemporary warm Arctic temperatures and large sea ice deficits (75% volume loss) demonstrate climate states outside of previous experience. Modeled changes of the Arctic cryosphere demonstrate that even limiting global temperature increases to near 2 °C will leave the Arctic a much different environment by mid-century with less snow and sea ice, melted permafrost, altered ecosystems, and a projected annual mean Arctic temperature increase of +4 °C. Second, even under ambitious emission reduction scenarios, high-latitude land ice melt, including Greenland, are foreseen to continue due to internal lags, leading to accelerating global sea level rise throughout the century. Third, future Arctic changes may in turn impact lower latitudes through tundra greenhouse gas release and shifts in ocean and atmospheric circulation. Arctic-specific radiative and heat storage feedbacks may become an obstacle to achieving a stabilized global climate. In light of these trends, the precautionary principle calls for early adaptation and mitigation actions.


Recent Arctic erosion and loss of permafrost along the Alaskan coast near Drew Point. Thawing land ice (white) is clearly visible. This is part of the current rapid changes happening in the Arctic. Photo from USGS (https://on.doi.gov/arctic-coasts).

Continue reading at: The urgency of Arctic change - ScienceDirect

Polar vortex breakdown | Arctic Sea Ice News and Analysis

In January 2019, a pattern of high-altitude winds in the Arctic, better known as the polar vortex, weakened, sweeping frigid air over North America and Europe in the second half of the month. Arctic sea ice extent remained well below average, but temperatures in the far north were closer to average than in past years.

The left image shows atmosphere winds (70 millibars, about 60,000 feet altitude) on January 15, 2019. North America is in the center of this view. The right image shows surface air temperatures on January 30, 2019. For reference, Chicago was -26 degrees Celsius (-15 degrees Fahrenheit) on this morning (dark blue color). Credit: earth.nullschool.net 

Arctic sea ice extent for January averaged 13.56 million square kilometers (5.24 million square miles). This was 860,000 square kilometers (332,000 square miles) below the 1981 to 2010 long-term average sea ice extent, and 500,000 square kilometers (193,000 square miles) above the record low for the month set in January 2018. January 2019 was the sixth lowest January extent in the 1979 to 2019 satellite record.

Continue reading at: Polar vortex breakdown | Arctic Sea Ice News and Analysis

The Keeling Curve: A daily record of atmospheric carbon dioxide since 1958 from Scripps Institution of Oceanography at UC San Diego

The Keeling Curve: A daily record of atmospheric carbon dioxide since 1958 from Scripps Institution of Oceanography at UC San Diego.

Global Warming Is Messing with the Jet Stream. That Means More Extreme Weather.

A new study links the buildup of greenhouse gas emissions to more frequent heat waves, floods and droughts in the Northern Hemisphere.

Greenhouse gases are increasingly disrupting the jet stream, a powerful river of winds that steers weather systems in the Northern Hemisphere. That's causing more frequent summer droughts, floods and wildfires, a new study says.


The speed and waviness of the northern jet stream, a river of wind across the Northern Hemisphere, is affected by the temperature difference between the Arctic and mid-latitudes. Credit: NASA

The findings suggest that summers like 2018, when the jet stream drove extreme weather on an unprecedented scale across the Northern Hemisphere, will be 50 percent more frequent by the end of the century if emissions of carbon dioxide and other climate pollutants from industry, agriculture and the burning of fossil fuels continue at a high rate.

In a worst-case scenario, there could be a near-tripling of such extreme jet stream events, but other factors, like aerosol emissions, are a wild card, according to the research, published today in the journal Science Advances.

Continue reading: Global Warming Is Messing with the Jet Stream. That Means More Extreme Weather.

A warming Arctic produces weather extremes in our latitudes

Atmospheric researchers at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now developed a climate model that can accurately depict the frequently observed winding course of the jet stream, a major air current over the Northern Hemisphere. The breakthrough came when the scientists combined their global climate model with a new machine learning algorithm on ozone chemistry. Using their new combo-model, they can now show that the jet stream's wavelike course in winter and subsequent extreme weather conditions cold air outbreaks in Central Europe and North America are the direct result of climate change. Their findings were released in the Nature online portal Scientific Reports on 28 May 2019.

Photochem. Photobiol. Sci., 2019,18, 717-746, DOI: 10.1039/C8PP90062K

For years, climate researchers around the globe have been investigating the question as to whether the jet stream's winding course over the Northern Hemisphere -- observed with increasing frequency in recent years -- is a product of climate change, or a random phenomenon that can be traced back to natural variations in the climate system. The term "jet stream" refers to a powerful band of westerly winds over the middle latitudes, which push major weather systems from west to east. These winds whip around the planet at an altitude of roughly 10 kilometres, are driven by temperature differences between the tropics and the Arctic, and in the past, often reached top speeds of up to 500 kilometres per hour.

But these days, as observations confirm, the winds are increasingly faltering. They less often blow along a straight course parallel to the Equator; instead, they sweep across the Northern Hemisphere in massive waves. In turn, during the winter these waves produce unusual intrusions of cold air from the Arctic into the middle latitudes -- like the extreme cold that struck the Midwest of the USA in late January 2019. In the summer, a weakened jet stream leads to prolonged heat waves and dry conditions, like those experienced in Europe in e.g. 2003, 2006, 2015 and 2018.

Continue reading at (with link to full-text scientific paper): A warming Arctic produces weather extremes in our latitudes

The State of Climate Adaptation in Public Health: An Assessment of 16 U.S. States | CAKE: Climate Adaptation Knowledge Exchange

Climate change poses significant threats to the health of individuals and communities, as well as the delivery of healthcare services. Human morbidity and mortality rates are rising due to extreme heat events and changing patterns of water-borne and vector-borne diseases, and healthcare infrastructure is at risk from extreme events. Climate adaptation actions are taken to either avoid or take advantage of climate change impacts either by decreasing vulnerability or increasing resilience.



Read more and access the report at: The State of Climate Adaptation in Public Health: An Assessment of 16 U.S. States | CAKE: Climate Adaptation Knowledge Exchange

Opinion | Agroecology as Innovation

On July 3, the High Level Panel of Experts of the UN Food and Agriculture Organization (FAO) released its much-anticipated report on agroecology in Rome. The report signals the continuing shift in emphasis in the UN agency’s approach to agricultural development. As outgoing FAO Director General Jose Graziano da Silva has indicated, “We need to promote a transformative change in the way that we produce and consume food. We need to put forward sustainable food systems that offer healthy and nutritious food, and also preserve the environment. Agroecology can offer several contributions to this process.”

The commissioned report, Agroecological and other innovative approaches for sustainable agriculture and food systems that enhance food security and nutrition, two years in the making, is clear on the urgent need for change. “Food systems are at a crossroads. Profound transformation is needed,” the summary begins. It goes on to stress the importance of ecological agriculture, which supports “diversified and resilient production systems, including mixed livestock, fish, cropping and agroforestry, that preserve and enhance biodiversity, as well as the natural resource base.”
Continue reading at: Opinion | Agroecology as Innovation