1. What happened to EU27 emissions in 2020 & what does it mean for the 55% 2030 target?
COVID19 sent CO₂ emissions down ~12%:
* Coal went down 18% in 2019, COVID cements this in
* Oil has grown last 5 years, 2020 needs to start a new decline
* Gas is stubborn, problem for 2030!
2. The EU target is for GHGs (not just CO₂), but now includes the forest sink.
The inclusion of the sink makes the relative reduction in emissions from 1990 larger (24% to 2018) & makes a 2030 target easier to achieve (in terms of reduced growth rates to achieve it).
But...
3. The inclusion of the land sink is probably necessarily to meet the 2050 net-zero GHG emission goal.
It may be hard to maintain the land sink, particularly in the face of climate change.
The alternative is using technical carbon removal (BECCS or DACCS, which have troubles).
4. Overall, the EU is well set to meet (& beat) the 2030 target.
* Changes are happening in the energy sector, with a rising EU-ETS price.
* The challenges will be reigning in transport emissions (oil) & turning the corner on gas.
5. The EU has already beaten its 2020 target, & may well make the 2030 target in a canter without using carry over credits (for those that know @ScottMorrisonMP's antics).
This means the EU has the potential to beat & up its 2030 target, which is necessary for <1.5°C.
/end
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An unprecedented 2.4 GtCO₂ (7%) drop in emissions in 2020 due to COVID19 restrictions. But, daily emissions are already edging up towards levels last seen in late 2019.
2. A drop of 2.4 GtCO₂ has not been seen before, but emissions have not been this high either.
After the global financial crisis emissions increased 1.7GtCO₂ in 2010. Will this record increase be surpassed in 2021?
Relative changes of >±7% were common before 1950...
3. Despite the rapid change in emissions, atmospheric CO₂ concentrations continued up as if COVID19 never happened.
Why?
* Emissions were high, as high as in 2012
* The relative change is smaller than interannual variability
* CO₂ is cumulative, so total emissions matter
Although the COVID-19 pandemic will cause a dip in 2020 emissions, this will not bring the world closer to the Paris Agreement goal of limiting global warming this century to well below 2°C & pursuing 1.5°C.
2. The Low Energy Demand (LED) scenario did not quantify costs "We have not explored [costs] in any detail, with the exceptions of the costs of supply-side ... However, this is a one-sided story without analogous quantifications of the demand-side ..."
A 𝘁𝗵𝗿𝗲𝗮𝗱 on how mitigation works, why we probably need some level of carbon capture & storage (CCS) & carbon dioxide removal (CDR) - just not as much as in scenarios.
2. We start with a baseline or reference scenario, that assumes no or limited mitigation. If we want to stay "well below 2°C" we need to get rid of the dark grey & be net-zero!
We can argue about the baseline, but for the purposes here, it doesn't matter nature.com/articles/d4158…
3. The heavy lifting is done by conventional mitigation: behavioural change, energy efficiency, fuel switching (fossils to non-fossils), changed transport, dematerialisation, etc, etc...
But, scenarios suggest this is not enough to get rid of all greenhouse gases.
2/ "As the IPCC points out, aggregate mitigation costs in IAMs generally increase when action is delayed. ... The longer mitigation is delayed, ... the more investments and/or devaluations it will therefore take to eventually bring emissions down to net zero/net negative."
3/ "The cost of mitigation is therefore not a function of continued fossil fuel use per se, but of the steepness of the mitigation curve, that is, of how quickly fossil fuel consumption needs to fall in order to reach the specified temperature target."
1/ "the availability of BECCS proved critical to the cost-efficiency, & indeed the theoretical possibility, of these deep mitigation scenarios, leading to systemic inclusion of BECCS in RCP2.6 scenarios" says @katedooley0, Christoff, @KA_Nicholas
2/ "The incorporation of NETs in IPCC scenarios is one clear illustration of how, as @EstherTurnhout put it, “dominant political discourses compel scientists to create assessments that work within these discourses”..." writes @wim_carton