What the 1.5 degree Celsius climate change threshold means?

12th September, 2021.      //   Climate Change  // 

1.5 degrees Celsius: the sad truth about our boldest climate change target  - Vox


This summer, the United Nations Intergovernmental Panel on Climate Change unveiled a new report forecasting dire consequences if the planet warms above a threshold of 1.5 degrees Celsius. Kate Konschnik, director of the Climate and Energy Program at the Nicholas Institute for Environmental Policy Solutions at Duke University, explains what that means and how climate scientists arrived at their conclusion.

A new UN study by the world’s top climate scientists revealed that we have now warmed the Earth by 1.2 degrees Celsius in less than 200 years. The Earth’s climate is getting so hot that in a decade, temperatures will likely blow past a level of warming that world leaders have sought to prevent. 1.5 degrees Celsius.  The target limit of 1.5 degrees Celsius.

According to Kate Konschnik; This is the difference between the average global surface temperatures of the planet before the Industrial Revolution and today. And so we’re always sort of using as a benchmark where we were before humans started on a massive scale burning fossil fuels. And then scientists are sort of comparing how much warmer has the globe gotten. 1.5 degrees or 2 degrees above pre-industrial revolution levels, there’s nothing truly magic about it, it’s sort of where policymakers have arrived.

But it’s based on sort of a scientific sense that once the globe gets on average each year that much warmer than it was before the Industrial Revolution, it potentially drives a lot more serious changes to our planet. One of the things I found most interesting about this latest IPCC report is that they explicitly were shifting from predictions and projections to forecasting.

Lot of the pushback and criticism of climate scientists and climate models have been there’s so much uncertainty in these models. How do we know you’re not just kind of saying sky is falling but maybe it won’t fall? And so do we really want to be changing our economy so dramatically when it’s so uncertain?

So the fact is that now they’re finding that projections they were making for right now are really pretty close to what we’re seeing right now. And so they’re getting a lot more confident. Those bands of uncertainty are shrinking. And so when they say now, hey, you can expect a lot more wildfires in the West in the next 10 years, then they’re saying that’s more of a forecast than a projection. That means we can expect with a lot of confidence that we’re going to be seeing more wildfires in the West.

What the IPCC report said is even if we meet these goals, a lot of change is in store for us in the future. If we don’t meet some of these targets, scientists are concerned we end up in in a so-called runaway effect where the planet then just starts heating up more and more and more of its own accord through its own natural systems because we’ve sort of set it off on this trajectory and we can’t walk it back.