If you ruled the world... when would you like carbon emissions to peak?
By Richard Black, Director @_richardblack
Published:24 September 2015
A bit of pain now, or a lot more pain tomorrow?
It’s the basic question of dentistry, but applies equally to climate change.
As a plethora of reports has concluded over the years, science indicates that there is a maximum amount of carbon dioxide that can be emitted if countries are to meet any target for limiting global warming – such as the one we have currently, of keeping it below two Celsius since pre-industrial times.
The looser the curbs are to start with, the faster emissions will have to come down later on; conversely, battening down the carbon hatch now would mean a more relaxed transition to a low-carbon economy.
‘A filling now or a tooth out later’ = ‘cut emissions now, or cut them much faster in years to come’.
‘When should emissions peak?’ is a pretty fundamental question, because the choices that governments make will have implications for us all.
But for all the reports that have looked at the question, we hadn’t seen anything that helps people outside the ‘climate bubble’ to engage with it. So we decided to create something.
And here is is…
The widget was created by a couple of people with whom ECIU had the good fortune to work earlier this year, Luke Sheldon and Helena Wright. Both recently gained PhDs from Imperial College London in complementary bits of climate change, Luke in climate modelling and Helena in adaptation and finance.
You can read the detailed methodology here; but in essence what they came up with is a computer model built to answer a single question: if global carbon emissions peak in a certain year, what has to happen to emissions in future years to stay below the 2ºC global warming target that all governments have endorsed?
The workings of the widget are based on techniques and assumptions that are pretty standard and available in the scientific literature. It's been validated by independent academics.
But of course, like any piece of modelling, the precise outputs depend on the inputs and assumptions. Someone else might do the same exercise and come up with somewhat different numbers.
It’s unlikely, however, that they would deviate from the fundamental conclusion: peaking emissions earlier means less pain down the line than peaking them later.
Blueprint for a better world
We’re launching the widget at an important time.
Heads of State and Government from pretty much all countries are heading to New York to sign off the Sustainable Development Goals (SDGs) – essentially, a blueprint for a future in which poor societies get richer, with better access to services such as health, education and energy, without further undermining the natural world.
Climate change is an integral part of the SDGs, with governments making commitments on climate protection alongside those on eradicating extreme poverty and hunger, doubling productivity of small-scale farms, and so on.
Governments are due to make more precise commitments in December, at this year's UN climate convention summit in Paris.
As always, their principal task will be to reconcile the scientific and economic rationale for reducing emissions – not to mention the popular mandate – with the short-term pressures to do little.
It’s worth noting that all governments have accepted the scientific evidence on carbon budgets and the case for early emissions peaking, by dint of having accepted last year’s report from the Intergovernmental Panel on Climate Change.
But what about you? What do you think – having played with the widget, would you prefer a filling now or an extraction later on?