Monday, January 04, 2016

To 2°C

There's been a lot of talk of strange weather, floods in the UK and many other places, droughts elsewhere, a record number of CAT 5 storms and the link to El Niño and global warming is now widely accepted. Much of the talk about flooding in the UK is around what should be done about this so-called 'new normal'. My prescription started here and was summarised in four key points in descending order of both importance and altitude:
  1. Slow down the rate at which water enters rivers.
  2. Divert water out of rivers on to land where flooding causes relatively little damage.
  3. Prevent water reaching homes and businesses.
  4. Get water into the sea.

It has been good to see that attention is being given to slowing water down before it reaches rivers, by reafforestation of uplands and creating leaky blockages to small streams, ponds, swales and other wetlands and a host of other farmland management practices.  The finger has been firmly pointed at the game-bird shooting industry, sheep farming, and subsidies that encourage farmers to do exactly the wrong thing.
Less attention has been given to what climate change we should be expecting over the next few decades.  The changes we are seeing are happening in a world that has seen only about 1°C of average global surface warming. There's at least another half degree already baked into the system even if we stop the rise of greenhouse gas concentration at its current level.  The recent Paris COP21 Agreement saw aspirational commitments towards a 50% chance of keeping the warming to 2°. Promised actions are leading us towards 3° and actual actions, if extrapolated, overshoot even that disastrous level.
But lets be optimistic, let's assume that the world's governments and peoples adopt strong climate mitigation measures and luck is on our side of the 50% probability and we do actually keep the global average surface temperature rise to 2°C.  When it comes to extreme weather event adaptation we should, rather than planning for more of what we have recently witnessed, be preparing for weather in a world where warming is double what we now see.
What weather should we expect in a 2° world and what do we need to do now to be able to cope with it?  That's where today's discourse needs to be.