Our world has grown complex enough that metrics matter. It is famously said that what doesn’t get measured doesn’t get managed. In climate science, our inability to produce simple metrics has delayed action while further polarizing the debate.
About 66% of scientists are convinced that more than half of the 0.8C warming of the past century is caused by human contributions of greenhouse gases. They and their interpreters in the media have convinced majorities of the public in most of the world that this is true. (That includes me, by the way, although I suspect a good part of the human contribution consists of black soot, deforestation and changes in land use / land cover.)
That’s because everybody is convinced about climate change, but not about climate consequences. Three things have to happen before public support for mitigation and adaptation will rise to a level permitting action without causing a revolution.
First, scientists will have to do a better job of attribution. What percentage of the temperature rise is due to natural variability, what part to greenhouse gases and what part to other human influences?
Second, scientists will have to provide a better range of sensitivity of the atmosphere to a doubling of CO2 concentrations. At its current level, the range of 1.5C – 4.5C is too wide to enable planning.
Third, everyone–scientists, politicians, lobbyists, NGOs, energy companies and the public–have to agree on a set of markers and metrics for the consequences of climate change. Currently, anything besides a lovely autumn day is labeled as a hellfire consequence of global warming. This has to stop. Currently, loss of ice in the major ice caps or the seas around them is counted in Manhattans. That’s absurd. Tell us percentages of the total. I really don’t care how many Hiroshimas are being detonated in the deep ocean. What was the temperature before? What is the temperature now? What will the temperature be in 10 year’s time?
Currently, the IPCC WG2 has a list of 26 key risks the planet can expect due to climate change. (Some of them, like loss of coastal areas due to sea level rise, are repeated for different parts of the world.)
What is needed is a series of progress (or regress) reports, saying X amount of coastline has been lost in the past decade and we are fairly confident that Y% of that X amount is due to sea level rise caused by global warming. Repeat for each of the 26 key risks.
Then put a price on it. The world has lost $X billion due to this loss of coastal area or our efforts to save it.
It’s a lot of work. If we unanimously agreed that it was worth doing it would still take a decade to come up with what I’ve requested.
But in an age where Merchants of False Certainty are crying doom and calling Barack Obama a denier, while some skeptics are still insisting that temperatures haven’t actually risen, we need to have plain language and simple numbers to show where we came from, where we are and where we may be going.
There’s a reason everyone trusts the Keeling Curve. It’s simple–it isn’t easy to misinterpret. Funnily enough, it’s about the only climate metric that isn’t abused by both sides.