There is a weird narrative in some quarters that wind and solar are pure good, while electric vehicles are a necessary (or even unnecessary) evil. This is wrong for many reasons. Yes, we should invest more in public transit and cycle more. We should also be more energy efficient.
But all replacements to fossil fuels will have impacts. Covering 14% of all the US land area with wind and solar farms is potentially doable – but it still has a big impact. EVs are heavier and thus potentially more deadly than ICEs, and batteries are GHG intensive to make.
This does not mean they are not worth doing. We can build much more renewables (and clean firm generation), invest in public transit, replace ICEs and EVs, etc. But if we pretend it will be small and beautiful rather than big and messy we are setting ourselves up for failure.
We can also find ways to help mitigate the negative impacts of clean energy technologies: prioritize making EVs lighter; create autonomous vehicle fleets to reduce the number needed; have a mix of clean firm and variable renewable generation to reduce overbuilding, etc.
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One of the biggest long-term impacts of climate change is sea level rise. Even in more moderate emissions scenarios we likely commit the world to many meters of future sea level rise over the next millennium – barring massive anthropogenic carbon removal in future centuries.
The folks at @ClimateCentral have an evocative new visualization of what sea level rise over the next ~1000 years would look like if it happened to cities today. They focus on a 3C warming case – consistent with best estimates of current policy outcomes: picturing.climatecentral.org
Of course, 1000 years is a long time. Who knows what our cities (or species) will look like that far in the future, what actions we might be able to take to slow down or reverse ice sheet loss, or what infrastructure we may build to hold back the rising seas.
The new @IEA 2021 World Energy Outlook provides more evidence that the world has moved away from high-emissions scenarios where coal powers the 21st century. We still have a long way to go to meet Paris Agreement goals, but are making real progress: thebreakthrough.org/blog/iea-repor… 1/12
The IEA WEO 2021 makes a number of notable changes to its scenarios. It extends its scenarios out to 2050 (vs 2040 in prior reports), and adds a new "announced pledges scenario" (APS) to model mid-century net-zero pledges that have proliferated over the past year. 2/
Heres a comparison of current policy (CPS), stated policy (STEPS), and announced pledges (APS) scenarios over time in the WEO. Note that IEA retired their CPS scenario after 2019, arguing that the world was moving too quickly for a current policy scenario to be of much use. 3/
Interesting op-ed on geoengineering today by @coralsncaves and @MichaelEMann. Unfortunately, I have to disagree with their suggestion that negative emissions technologies (NETs) are "unlikely to make a meaningful dent in atmospheric CO2". thehill.com/opinion/energy…
A thread: 1/14
In the article they note that IPCC scenarios that peak warming at 1.5C by mid-century later involve substantial drawdown of atmospheric CO2 that prevents further increases in surface temps and is followed by global-scale cooling after emissions go negative. 2/
This is broadly accurate; for example, the new SSP1-1.9 scenario overshoots mid-century resulting in around 1.6C warming, before falling back to 1.4C by 2100 though a very aggressive deployment of net-negative emissions: 3/
Oil and gas prices have been skyrocketing in recent months. This is effectively a carbon price – and a pretty high one at $67 per ton CO2 for oil and $62 per ton for gas relative to January 1st 2021 prices – but only as long as prices don't fall: nytimes.com/2021/10/04/bus…
Note that while expensive oil and gas can make clean energy alternatives more cost-competitive, there are real equity impacts on poor households for whom energy is a non-trivial part of their budget.
My assumptions (in case its helpful):
oil_price = 77 - 48. //dollars per barrel
oil_carbon = 0.43080 //tons per barrel
gas_price = 6 - 2.6 //dollars per million btu
gas_carbon = 0.0544311 //tons per million btu
A number of folks have argued that warming will happen faster than we expect because scientists are not accounting for falling emissions of planet-cooling aerosols as we reduce fossil fuel use. This is not the case – all our future scenarios account for rapid aerosol declines:
Aerosols currently cool the world by around 0.5C (with a fairly large uncertainty). This figure from the recent IPCC AR6 shows the warming since preindustrial times associated with each different factor that contributes to climate change:
In both scenarios consistent with current commitments (SSP2-4.5) and deep mitigation (SSP1-1.9 and SSP1-2.6), cooling from aerosols is cut by 4/5ths, down to ~0.1C by 2100. Most of this reduction happens in the next few decades:
If the proposed Clean Energy Performance Program becomes law it will severely penalize utilities for closing existing nuclear plants. We estimate that closing the Diablo Canyon plant would cost PG&E somewhere between $500 million and $1.5 billion: thebreakthrough.org/issues/energy/…
CEPP awards utilities with a payment of $150 per MWh for an increase in year-over-year clean energy generation of over 1.5 percentage points if the total increase year-over-year exceeds 4 percentage points.
For example, if a utility had 20% of the electricity generation from clean sources in 2022, and increased that to 24% in 2023, they would be eligible for a payment of $150 per MWh for 2.5% (4% minus 1.5%) of their total generation.