Warmest Decade
Climate Change Daily Repost

The warmest decade

The map above shows 2019 average temperatures compared to average temperatures from 1955 to 1965. Red indicates an increase in temperatures and blue areas show a decrease (Source: NASA)

So, NASA and NOAA both agree that 2016 and 2019 were the two hottest years on record. The average global temperature was up 1 degree Celsius from the 1950s. The year 2019 topped off the warmest decade in recorded history. However, the average global temperature increase doesn’t tell the real story since an average evens out a wide range of temperature variations around the globe. The average number masks critical information about regional temperature increases. These regional increases therefore tell the real story about climate change and its implications for the future.

It matters if global temperatures rise. But it matters even more how that average rise distributes itself geographically: Location, Location, Location. Geographically speaking, some places are more favorable than others for higher temperatures, particularly if you are one of the 600 million people who live within 10 meters of sea level. An extra 6°C temperature rise at the equator will melt the ice in your drink as you sit on the beach and watch a sunset. However, an extra 6°C rise at the North Pole will melt the Arctic ice, and there won’t be a beach for you to sit on.

Location

Regional temperatures: Location, location, location

It matters if global temperatures rise. But it matters even more how that average rise distributes itself geographically.

The warmest decade in recorded history topped off by one of the warmest years – so where did average temperatures increase and decrease the most?

Australia

The year 2019 was a tough year for the folks Down Under. Average temperatures were 1.5 degrees Celsius (2.7 Fahrenheit) higher than in the 1960s. Some of the worst wildfires in the world ravaged the country.

Penrith, a suburb of Sydney, registered 48.9 degrees Celsius or 120 degrees Fahrenheit one Saturday during the heatwave. This extreme heat followed the driest spring on the continent since records began 120 years ago. Additionally, these arid conditions came on top of a string of previous dry seasons. New South Wales and Queensland have been short of rain since 2017.

Deaths, mass evacuations, 12 million acres burned, and half a billion animals killed – The 2019–2020 Australian fires will not be easily forgotten. As Andrew Constance, the transport minister, told the news, “This is not a bush fire. It’s an atomic bomb.”

Alaska

The Arctic has seen average annual temperatures rise almost 6 degrees Celsius since the middle of the last century, a whopping six times greater than most of the planet. The Arctic is warming much faster than the rest of the planet, and Alaska shares in the Arctic heatwaves

Warm Earth

Arctic Warming

Arctic warming is significant because it triggers two feedback processes that strengthen the rate of global warming

In March of 2019, temperatures in northern Alaska were 42 degrees Fahrenheit or 20 degrees higher than normal, and the year 2019 was the hottest on record for the State. Permafrost is thawing, and glaciers are melting in the summer heat.

Northern Plains

However, temperatures fell in some areas like central Canada and the Northern Plains of the USA. The average annual temperature in the center of North America was lower in 2019 than in the 1960s. But part of the irony of climate change and global warming is that some areas may get colder.  

As the earth heats up, the effects will not be evenly distributed because the earth deals with heat through a dynamic process involving atmospheric and oceanic circulation. Air and water currents can move heat from one area to another. The net effect is that heat dissipates in some areas and concentrates in others.

When global warming weakens the polar vortex and causes the jet stream to slow down, then this slower moving jet stream is more prone to meander and develop waves or lobes that carry blasts of polar air southward into mid-latitudes. This effect is what chilled the north-central USA.

A total of 19 of the 20 hottest years on record occurred in the 21st century, and the years from 2010 – 2020 form the warmest decade yet. Anthropocene climate change is firmly rooted and all expectations are that it will only get hotter.


Sources:

2019 Was the Second-Hottest Year Ever, Closing Out the Warmest Decade (By Henry Fountain and Nadja Popovich; New York Times) – https://www.nytimes.com/interactive/2020/01/15/climate/hottest-year-2019.html  Also:

NASA, NOAA Analyses Reveal 2019 Second Warmest Year on Record (Source: NASA) – https://www.nasa.gov/press-release/nasa-noaa-analyses-reveal-2019-second-warmest-year-on-record   Also:

Why some spots on the planet are heating up faster than others (By
Sarah Kaplan; Washington Post) – https://www.washingtonpost.com/climate-solutions/2020/05/20/climate-change-hotspots/ Also:

Feature Image: Temperature Anomaly 2019 (Source NASA) – https://data.giss.nasa.gov/gistemp/maps/index_v4.html


William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.

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