PLEA Network

8 June 2017, The Conversation, What is a pre-industrial climate and why does it matter? Over the past few days there has been a lot of talk about the Paris climate agreement, from which the United States is planning to withdraw. Although this is a setback, there is still near-complete consensus from the world’s governments that a strong effort to tackle climate change is needed. The Paris Agreement aims to limit global warming relative to a pre-industrial baseline. Its precise commitment is: Holding the increase in the global average temperature to well below 2℃ above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5℃ above pre-industrial levels, recognising that this would significantly reduce the risks and impacts of climate change. But this begs the question: what are “pre-industrial levels”? Clearly, if we’re aiming to limit global warming to 1.5℃ or 2℃ above a certain point, we need a common understanding of what we’re working from. But the Paris Agreement doesn’t provide a definition. This becomes key as governments expect climate scientists to coherently compare different plans to reach their Paris targets. It’s crucial to be clear on what researchers mean when we say “pre-industrial”, and what assumptions our projections are based on. Of course, as the chart below shows, no matter which baseline we use it’s clear there’s been a drastic rise in global temperature over the last century. Read More here