http://www.vox.com/energy-and-environment/2017/3/23/15028480/roadmap-paris-climate-goals
Scientists made a detailed “roadmap” for meeting the Paris climate goals. It’s eye-opening.
In 2015, the world’s governments met in Paris and agreed to keep global warming well below 2°C, to avoid the very worst risks of a hotter planet. See here for background on why, but that’s the goal. For context, the planet’s warmed ~1°C since the 19th century.
One problem with framing the goal this way, though, is that it’s maddeningly abstract. What does staying well below 2°C entail? Papers on this topic usually drone on about a “carbon budget” — the total amount of CO2 humans can emit this century before we likely bust past 2°C — and then debate how to divvy up that budget among nations. There’s a lot of math involved. It’s eye-glazing, and hard to translate into actual policy. It’s also a long-term goal, a distant target, easy for policymakers to shrug off.
So, not surprisingly, countries have thus far responded by putting forward a welter of vague pledges on curbing emissions that are hard to compare and definitely don’t add up to staying below 2°C. Everyone agrees more is needed, but there’s lots of uncertainty as to what “more” means. Few people grasp how radically — or how quickly — we’d have to revamp the global economy to meet the Paris climate goals.
Surely there’s a better, more concrete way to think about what’s required here. And a new study out today tries to do just that. Fair warning: It’s jaw-dropping.
A simple (but daunting!) road map for staying below 2°C
In a new paper for Science, a group of European researchers lay out a more vivid way to frame the climate challenge — with details on what would have to happen in each of the next three decades if we want to stay well below 2°C.
see paper at Science at
http://science.sciencemag.org/content/355/6331/1269 
