How Much Climate Change?

It would be easy to come away from a lot of today's climate change media coverage concluding that average global temperature change will be limited to 2^o C, a number chosen years ago to represent (without any particular scientific basis) the threshold beyond which lies “dangerous” climate change.

There is no reason to assume, however, that average global temperature change will be limited to 2^o C, much less the more aggressive target of 1.5^o C. Assuming that one of these targets will be achieved “because it must be,” as is common in both societal and business climate risk discussions today, reflects a "false certainty." The plausible range of potential climate change outcomes is actually much larger:

• 5^o C is not out of the question given the known unknowns of the climate system and the possibility of unknown unknowns.

• 3-5^o C represents today’s most likely climate outcome by 2100, based on “stay the current course” climate policies and measures.

• 2^o C scenario is today’s prevalent climate change target, but one that would require much more aggressive mitigation actions than we have yet seen.

• 1.5^o C roughly represents the idea of returning CO₂ concentrations in the atmosphere to 350 ppm; it is being called for by scientists and activists around the world, but would require extraordinary mitigation efforts.

Business decision-makers need to watch potential shifts in the likelihood of one temperature outcome or another. A clear indication that the world will act to achieve a 2^o C or 1.5^o C target, for example, would have huge business implications from a policies and measures perspective. A clear indication that global temperatures will reach 3^o C or 4^o C would have similarly huge business implications, albeit very different ones.

With Your Climate Change MBA you can explore the drivers and impacts associated with each of the scenarios introduced above, and in the case of the last two scenarios the policies and measures that would be required to achieve them. You’ll also see an assessment of the likely business ramifications of each scenario, and be hyperlinked to more resources and curated information collections in the Climate Web.

You can track the evolution of many key variables underlying these scenarios via the Business Materiality Dashboard, also profiled in the Decision Support chapter of Your Climate Change MBA.