Goal of @wim_carton talk on #negativeemissions is for everyone to understand twitter joke about #beccs by @DoctorVive & why it’s funny. Great meta #scicomm! 
Paris Agreement aims to stabilize climate thru “balance of sources and sinks”. @wim_carton gives overview of various negative emissions tech - all aim to prevent/remove carbon from atmosphere and transfer to land/geology/oceans.
Here’s what bioenergy with carbon capture and storage #BECCS looks like. Burn vegetation for energy, capture carbon. @wim_carton
Do we need negative emissions (taking carbon out of the atmosphere)? IPCC says yes for 1.5deg and 87% of pathways for 2deg (most about 1/3 of all carbon added to atm since industrial revolution).
BUT. Negative emissions are primarily a function of assumptions about social & economic systems and inertia, not biophysics. They’re a debt mechanism to pay off overshooting our carbon budget. Letting us burn more #fossilfuels and increase GDP, says @wim_carton. (Yay?)
BECCS are ultimately a political question, we cannot reduce it to something a model can tell us, argues @wim_carton. They are the result of models requiring cost optimization over justice, risks, etc. We should have political conversations about this.
Why are #BECCS popular? They mean we can stop using #fossilfuels more slowly. Potentially can drawdown CO2 in atmosphere. And they’re cheap (but @wim_carton asks, valuing what and for who?)
What’s the problem with BECCS asks @wim_carton. Oh no biggie we just would have to use 1/3 of cropland for growing non-food
BECCS assumes rapid yield increases will free up land for bioenergy shows @wim_carton. If this doesn’t happen, it’s a problem (ie could need more deforestation for food).
What about planting 🌲? Afforestation = new forest, reforestation = replanting previous forest.
Sounds good, but in practice: 45% of country climate plans use large-scale timber production. Tend to neglect rights, risks, trade offs, justice, shows @wim_carton
Sounds good, but in practice: 45% of country climate plans use large-scale timber production. Tend to neglect rights, risks, trade offs, justice, shows @wim_carton
What about direct air capture? Biz friendly (tech bro dream), doesn’t create conflicts with farmland. BUT need new industry the size of current #fossilfuel industry, with high costs and energy, currently no business case to do this. @wim_carton
Current uses for captured carbon: enhanced oil recovery (more #fossilfuel production!) and synthetic biofuels, shows @wim_carton
we just cannot get our heads around not burning carbon.
we just cannot get our heads around not burning carbon.
Scientists doubt that carbon removal will work. Many concerned about the lack of realism in over reliance in scenarios, shows @wim_carton
Moral hazard of negative emissions: we keep emitting now, transfer risks to next generations. “We believe we can do this- You figure it out” says @wim_carton. @Risk we burn our carbon budget now and lock in dangerous warming. Reduces push for rapid near term reductions.
Moral hazard in reality: @Shell claims we can burn #fossilfuels throughout 21st century and use risky/unproven negative emissions to perhaps stay below 2deg. Meanwhile Shell boss says he has “no choice” but to keep investing in #fossilfuels, shows @wim_carton
the market is trying to find a way to profit from carbon. What the atmosphere responds to is how much carbon is emitted. Under current system, markets will not deliver climate stabilization- may need massive government subsidies to oil majors to #KeepItInTheGround ? @wim_carton
Conclusions: negative emissions are popular because they avoid unpopular realities. @wim_carton is interested in research question if carbon removal could ever be done to support near-term mitigation with co-benefits?
