Thread by @mark_lynas

New Nature paper out today
nature.com/articles/s4158…
states very clearly what is needed if governments are serious about limiting global heating to 1.5C, as agreed at Paris.

Spoiler: No new fossil fuelled infrastructure, anywhere, ever. From now on.

Read thread for details...

Existing infrastructure - if operated until the end of its lifetime - commits us to 658 billion tonnes (Gt) CO2 future emissions. That's -

358 Gt from electricity (mainly power plants)
162 from industry
64 from transport, mostly on-road vehicles

But there's more: over 1,000 GW of fossil-fuelled power plants are planned, permitted or in construction. (20% in China).

That gives us another 188 Gt committed future CO2 emissions.

TOTAL: 846 Gt "if all proposed plants built and all infrastructure operated".

According to the IPCC, our remaining 1.5C carbon budget is 420-580 Gt CO2. (To have a 50-66% chance of limiting warming to 1.5C)

What does this mean? It means ALL PLANNED, PERMITTED AND UNDER CONSTRUCTION fossil infrastructure must be CANCELLED. Paging @ExtinctionR !

Done? OK, so now take the 188 from the 846 - but still leaves 658 Gt of committed emissions. Damn! Still over budget.

Therefore... to have a better than 50:50 chance of meeting the 1.5C goal another 100-200 Gt-equiv of power plants, cars, industry etc MUST BE CLOSED EARLY.

Or we ditch the 1.5C target and go for 2C instead. That means:

- 99% of coral reefs extinct
- 65 million more people exposed to deadly heat
- 2x as many plants, 3x animals lose 50% of their habitat as 1.5C
- Arctic sea ice disappears
- 10 million displaced by rising seas

... and much more (as I'll outline in the new Six Degrees book). The carbon budget for 2 degrees is bigger, 1170-1500 Gt CO2. Phew - still some wriggle room then!

But keeping to this bigger 2C budget means:

...reducing emissions by 5% per year STARTING FROM NOW. Not 2030, now.

Other options the authors suggest to stretch the budget:

- Massive retrofit of carbon capture & storage (ain't gonna happen)
- Large-scale negative emissions (trash the biosphere with BECCS)
- "Solar radiation management" (geoengineering - ugh)

Here's what we need to do:

- No new coal or gas power plants, anywhere, ever.
- Immediate transition to fully electric transport (no more diesel, petrol)
- Stop all oil/coal/gas exploration (bye bye Shell/BP/Exxon)
- Massive renewables+nuclear deployment
- Decarbonise industry

But where are we ACTUALLY heading?

- carbon emissions at an all-time high, 37Gt in 2018, 2% annual growth: globalcarbonproject.org/carbonbudget/1…
- current policies still take us potentially over 4 degrees = climate catastrophe
climateactiontracker.org/press/cat-annu…

And if we fail? What does 4 degrees or above mean in terms of climate impacts?

*shudder*

This is a CLIMATE EMERGENCY.

/the end