As 2020 comes to a close, we're taking a look back at some of our best reporting on the environment.

The whiteness of this piece on "climate refugees" (corrected link) is deep.

The piece centers the story of Jen and Ryan Cashman, a white couple + their kids who used to live in Paradise, California.

It does include an interview with Dr. @JalonneWNewsome who explains that climate change hits folks of color harder, and they may be less able to move due to fewer economic resources + less willing to move b/c of greater ties to their communities.

After this perfunctory nod to her excellent work, then the reporter (*cough* abuser *cough*) goes on to segue with one of the biggest "yeah, buts" I've ever heard...

"If you have the luxury of choosing where to live and climate change is a factor, here's the formula..."

Thread on snow ratios. The snow ratio, or snow-to-liquid ratio states how many inches of snow, when melted, yields one inch of liquid water. Ratios are usually around 10:1 or 12:1, but can vary from as little as 6:1 or as high as 30:1, or sometimes more. 1/

There's a common misunderstanding that the colder the surface temp is, the higher the snow ratio will be (fluffier snow). This is incorrect. As long is the surface temp is not close to freezing, it really doesn't matter all that much. 2/

As the surface temp gets close to or exceeds freezing, more snow is lost to melting, yielding lower ratios and heavy, wet snow. The same reasoning also applies to temps above the ground; if they exceed freezing, sleet or rain can mix with the snow, dramatically lowering ratios 3/

Much more important is the dendritic growth zone (DGZ), the layer of the atmosphere with temperatures between -12 and -18C. In this layer, snowflakes grow as dendrites, which can easily clump together into aggregates, which contain a lot of air, increasing the ratio 4/

At warmer or colder temps, the flakes grow as plates, columns, or needles, which don't clump together as well and contain less air, lowering the ratio. To make this even more complicated, there's also a dependence on atmospheric humidity. 5/

Earth has a fever in more ways than one. Some places averaged + 5-7 °C warmer than normal for the ENTIRE YEAR of 2020.

An enormous area of anomalous warmth plagued Arctic Siberia effectively all year but it was not just the Arctic where we saw record shattering warmth.

THREAD

Another way of looking at it... Very few cold blobs left. La Niña developed and shows up in the Pacific.

The climate is not changing uniformly, the Arctic is warming much faster than the rest of the world.

Data: @CopernicusEU and compares to 1981-2010 average.

JANUARY was joint hottest January globally on record according to NASA GISTEMP v4 (joint record with 2016).

Profound winter warmth for North America plus Europe and Asia.

FEBRUARY was second hottest on record (1st place is still held in 2016).

The winter 'warmth' in Europe and Asia was just insane.

MARCH: A cold Canada, Greenland and Svalbard... but obvious warmth still striking across the continents, particularly northern/central Asia.

This was the second hottest March on record (2016 still holds the record).