Expect More Extreme Weather
According to Sam Carana of Arctic News, we can expect more extreme weather.
The heaviest rains and floods in 120 years have hit Serbia and Bosnia this week, Reuters and Deutsche Welle report.
The animation below shows the Jet Stream’s impact on the weather. Cold temperatures have descended from the Arctic to Serbia and Bosnia in Europe and in central North America, while Alaska, California, and America’s East Coast are hit by warm temperatures. In California, ‘unprecedented’ wildfires and fierce winds lead to ‘firenadoes’, reports CNN.
The image below shows that on May 15, 2014, the wind approaching Serbia and Bosnia at 700 hPa reached speeds of up to 120 km per hour (75 mph), as indicated by the green circle on the main image and inset.
As the Jet Stream changes, more extreme weather events can be expected. What makes the Jet Stream change? As the Arctic is warming up faster than the rest of the world, the temperature difference between the Arctic and the equator decreases, in turn decreasing the speed at which the Jet Stream circumnavigates the globe. This can cause ‘blocking patterns’, with extreme weather events hitting an area longer than before.
As the jet stream becomes wavier, cold air can more easily descend from the Arctic down to lower latitudes where the jet stream reaches lower, while warm air can more easily reach higher latitudes where the jet stream goes up higher.
This spells bad news for many areas across the world that can be expected to be hit by more extreme weather events such as heatwaves, wildfires fueled by stronger winds and more intense drought, storms and floods.
Heatwaves are a huge threat in the Arctic, especially when followed by storms that can cause warm surface water to mix down to the bottom of the sea and warm up sediments under the seafloor that can contain huge amounts of methane in the form of hydrates and free gas. The situation is dire and calls for comprehensive and effective action, as discussed at the Climate Plan blog.