. @theAGU hosts a massive conference of Earth and space scientists every December, usually in San Francisco (photos below from previous years). My 1st meeting was in 2003 as a masters' student. In this #thread I'll share highlights from #AGU20, my first time attending virtually!

#Agriculture (esp replacing forests with cropland) has been changing the #climate for 6,000+ years. Ancient warming made Europe + East Asia more suitable for cultivation, lengthened Eur. growing season, find @Chris_Kucharik @NRamankutty et al. #AGU20
…https://agu2020fallmeeting-agu.ipostersessions.com/?s=9B-D8-01-CF-47-DD-24-C2-5B-6D-C0-70-CD-9E-74-6A

Something cool I discovered this year at #AGU20 (thanks to @KateBrauman) is the MacGyver session, w/ hacks including a test for #COVID19 in wastewater & a system to lure vineyard pests away with mating calls instead of harmful sprays. https://agu.confex.com/agu/fm20/meetingapp.cgi/Session/103650

Great talk about using #nature to fix #climate (negative emissions) by @connornolan #AGU20:
-avoided #deforestation is key for conservation- but doesn't take up *additional* carbon.
-natural climate solutions "at risk from the problem they're trying to solve" (warming) (1/n)

@connornolan #AGU20 2/n:
California estimates nature can do 20% of the #carbon work needed- no getting around eliminating fossil fuels! ( https://www.climateworks.org/programs/carbon-dioxide-removal/getting-to-neutral/)

@connornolan #AGU20 3/n:
Helpful concept of natural climate solutions: are they replacing historical carbon lost from ecosystems ("silo") or providing substantial additional carbon storage ("haystack")? (If silo, natural land uptake may have already done most of the work...)

@connornolan #AGU20 4/n:
Of 42 estimates of negative emissions from natural climate solutions, only the most bullish are in the range needed for 1.5°C. Papers that recognize only tropical reforestation helps cool temps, + included carbon price, estimated lower uptake potential.

Land tenure, finance, measurement of carbon uptake esp in soils are key challenges for implementing natural climate solutions at scale.
@connornolan #AGU20 5/n:

@connornolan #AGU20 6/n: nice summary of tradeoffs and constraints between different natural climate solutions.

Study ( https://www.nature.com/articles/s41558-020-0856-3) found considering "constraints" (reality on the ground), only 0.3-18% of estimated carbon uptake from ecosystems could be realized. :(

Clear potential for land biosphere to remove atmospheric carbon, but "the first billion tons are more difficult and slower than assumed, and the ultimate total is likely less than we need," likely 100-200 Gt CO2 concludes @connornolan #AGU20 7/7( (w/ @chrfield @katharine_mach)

This 12 minute talk by @connornolan on why nature is important and helpful but won't save us from #climatechange is well worth a watch! #AGU20 https://agu.confex.com/agu/fm20/meetingapp.cgi/Paper/755337

(spoiler alert, to stabilize #climate we have to stop burning #fossilfuels)