The forests of Russia, Mongolia, Canada, Scandinavia and the US will experience unprecedented destructive heat by 2029 with staggering consequences for life on Earth.

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/

Many wonder how epidemiology could have become so politicized. But epidemiology - like climate science (the other "mysteriously politicized" subject) has intrinsic politics: to take epidemiology seriously, you have to acknowledge that our species has a shared destiny.

1/

Much of the debate over "liberty" can be summed up as "you do you" - I'll swing my arm over here, you keep your nose over there, and so long as we both respect each others' "freedom," I won't punch you in the nose and your nose will remain unpunched.

2/

This breaks down when applied to epidemiology: "You wear your mask, I'll leave mine at home, and we'll both exercise our freedoms" is like "You swim in the no-pissing end of the pool, I'll swim down here in the pissing end, and we'll both get our way."

3/

We're in the same epidemiological pool, and the science is clear: masking's benefit is primarily in protecting others from you - your presymptomatic, asymptomatic (or symptomatic) spread of particles. Your decision not to wear a mask puts me in danger.

4/

If your worldview ascribes political outcomes to individual choices (implying that poverty or misfortune are the result of a combination of laziness and inferiority), then anything that demands a systemic view challenges its very foundations.

5/

Just as no amount of flat temperature data would dissuade the climate cult, so no amount of flat (or even negative!) data on mask effectiveness will shake the faith of the Church of Covid. Beautiful Theories cannot be disproven by mere information.

The "Covid emergency" will never be over. It will mutate and seek out new missions when this particular virus threat abates, repurposing its funding and clinging to its power. They're already talking up the "next pandemic" and how we must forever remain at DEFCON 2 to be ready.

Masks are now a visible and tangible symbol of an entire agenda. Its champions will use every means possible to force you to wear them forever, including corporate pressure, their new favorite tool. Expect commercial mask requirements to linger, especially big corporations.

True believers, meanwhile, will wear their masks with grim determination and scowl ostentatiously at everyone who refuses to join them. It's a new virtue signal that will not go away any time soon. Mask scolding is a quick, easy, heady power rush.

All the while, studies will keep rolling out that masks don't help, and might even hurt. That was fairly common medical knowledge before the pandemic began, but it was aggressively suppressed when masks became a political symbol, and a totem for people desperate to DO SOMETHING.

It's (nearly) five years since the Paris Agreement was gaveled through… but was it any good? Tricky question. Based on emissions, temperature data and impacts, no. *But...* (thread)

The team at @SystemIQ_LTD have crunched the numbers & reviewed how far + fast sectors have shifted since 2015. Their take is the global economy could be a decade away from seismic tipping points that see the world move fast towards low carbon.

In 2015, zero-carbon technologies and business models could rarely compete with incumbent carbon-solutions. In 2020, zero-carbon solutions are competitive in sectors representing around 25% of emissions. In 2030 the figure’s looking like 70%.

What does this mean for a COVID-smashed world, where 2021 is shaping up to be a hellish mix of recessions and mass unemployment? Well, the 2020s could see a net increase of 35 million low carbon jobs if governments roll out the right policies + invest wisely.

Can the low carbon acceleration be pinned to Paris? Not entirely, but partly. In 2014 no-one talked of net zero targets. Now 120+ countries either have these plans or are working on them. By mid 2021 the US, China, EU, UK, Japan, Korea, Canada will have these targets.