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University of ManchesterJune. 2015
Kevin Anderson
web: kevinanderson.info
2°C Carbon Budgets for Wales a focus on energy-CO2 only
twitter: @KevinClimate
Our headline conclusion:
Avoiding “dangerous climate change” (stabilisation at 2°C) remains a feasible goal of the international community
just
…but the probabilities are no longer good
IPCC Synthesis Report
“Cumulative emissions of CO2 largely determine global
mean surface warming by the late 21st century and beyond”
That is, the temperature increase by ~2100 (compared with the pre-
industrial period) relates to the total quantity of carbon emitted since the
industrial revolution.
i.e. our emissions are constrained to reside within 2°C carbon budgets
Estimating energy-only CO2 budgets from 2015 to 2100
We need to note that:
Since 2011, we’ve emitted about ~150GtCO2 (~15% of “likely” 2°C budget)
Deforestation & land-use change from 2015-2100 ~100GtCO2
Cement process emissions from 2015-2100 ~150GtCO2
i.e.: … to subtract, at least 400GtCO2 from the energy budget from 2015
… to stay below 2°C
600(66%)
900(50%)
1100(33%)
i.e.: the budgets from 2015 -2100 for CO2 from energy only
2015
Considering poorer (non-Annex 1) nations:
1. Peak 2025; mitigate 10% p.a. from 2035 650
2. Peak 2025; mitigate 5% from 2035 900
3. Peak 2030; mitigate 5% from 2035 1200
GtCO2
(2015-2100)
1. 66% 50% 33%
2. 66% 50% 33%
3. 66% 50% 33%
✗✗ ✗✗ ✗ ✗
Consider these in relation to 2°C budgets …
Considering wealthier (Annex 1) nations:
1. Peak now; mitigate 5% p.a. from 2025 350
2. Peak now; mitigate 10% from 2025 220
3. Mitigate 10% p.a. from now 130
GtCO2
(2015-2100)
Put bluntly
66% chance of 2°C is lost
50% chance demands a war-like footing on mitigation- Wealthier nations 10% p.a. within a few years- Poorer nations 10% p.a. by 2035
33% chance still demands mitigation rates far beyond anything countenanced before, at Bonn last week & probably at Paris in Nov.
We have 25 years of explicitly choosing to fail on 2°C(WGIII & IAMs?)
But it is a choice!
Can this framing of 2°C be reconciled with:
“To keep … global average temperature rise close to 2°C … the UK [must] cut emissions by at least 80% … the good news is that reductions of that size are possible without sacrificing the benefits of economic growth and rising prosperity.”
UK Committee on Climate Change
“To keep a good chance of staying below 2°C, and at manageable costs, our emissions should drop by 40 to 70 percent globally between 2010 and 2050, falling to zero or below by 2100”.
... mitigation costs would be so low that “global economic growth would not be strongly affected”
IPCC Chair Nov. 2014
WGIII Co Chair Nov. 2014
Why does orthodox analysis give such different results?
Probability of exceeding 2°C is much higher (60-80%)
i.e. bigger carbon budgets
Inequitable apportionment of global emissions to Annex 1
Inappropriate assumptions on deforestation & cement
Unfeasibly (Machiavellian?) early peak dates
Geo-engineering is ubiquitous in low carbon scenarios
Systemic bias – time travel & geo-engineering
The UNEP Gap Report (basis for Welsh & UK Gov’t policy) contains:
163 scenarios for 50% or better chance of 2°C; of these:
- 140 peak CO2 in 2010
- 23 peak in 2020, all of which include geo-engineering
So all require an ability to travel back in time or the large-scale
uptake of highly speculative negative emission technologies
Almost three quarters of the scenarios are dependent on both time
travel and geo-engineering
A reminder of what Wales et al have committed to:
… to make our fair contribution to…
“To hold the increase in global temperature below 2 degrees
Celsius, and take action to meet this objective consistent
with science and on the basis of equity”
Copenhagen Accord, 2009
Apportionment principles, rules, or guidelines
Responsibility spread evenly across all nations (no equity concern)1. Cumulative Population 2015-21002. Emissions share 2012
Responsibility greater for wealthier (Annex 1) nations (weak equity)3. Non-Annex 1 peak CO2 in 2030 – 10% pa. mitigation by 20404. Non-Annex 1 peak CO2 in 2025 – 5% pa. thereafter
… remaining Annex 1 CO2 divided as in 1 & 2 above
✗
CO2-energy budgets for Wales 2015-2011
Even for a 33% chance of 2°C (i.e. a 67% of exceeding 2°C),
Wales has a budget range of 467 to 711 MtCO2
i.e. 11 to 18 years of current emissions
Why so different to the UK/CCC position?
No geo-engineering
Recognition it’s now 2015
Deforestation & Cement (process) accounted for
Less inequitable apportionment of the global budget