In the post-Paris Accord climate world, analysis of theoretical scenarios that have a reasonable likelihood of keeping global temperatures “only” 1.5°C warmer than pre-Industrial have become all the rage (one of the latest examples I’ve seen). I’ve written posts about the mythology associated with 2°C scenarios given the reality of countries’ CO2 emissions historically. Given that reality, 1.5°C scenarios reside further in the realm of fantasy.
The primary reason is the lack of scalable technologies to remove CO2 from the atmosphere. That is not a judgment statement, it is an observation about how things exist in the real world. Theoretical studies have their utility. My ongoing anxiety revolves around policy makers’ dependence on those studies to inform their decision making.
The resources required to deploy global-scale renewable or nuclear energy are mind-boggling enough. If we need to add to that infrastructure additional technologies that remove CO2 from the atmosphere, it strikes me as obvious that we need to be sober about our expectations to do so.
For the record, decisions like the Canadian government’s to purchase the Kinder Morgan’s Trans Mountain pipeline for C$4.5bn (US$3.45bn) will result in higher future requirements to deploy additional renewable energy and CO2 removal technologies. They make it harder to achieve the already fantastical targets that many climate activists are focused on. The decision ensures that the recent plateau in CO2 emissions will remain a historical anomaly:
Set in the context of future emission scenarios, the decision should be framed more as one that locks us into a warmer global future:
To have any hope of a <2°C world, global CO2 emissions need to peak. They haven not done so as of 2017 and likely will not in 2018 or in the following handful of years, absent some financial or geopolitical disaster. The right hand time series is clear: if we continue emitting anywhere near 35-40 GTCO2 every year, it becomes increasingly likely global temperatures will rise to 3-4°C by 2100.
The difference between 1.5°C and 2°C sounds very small to most people. The impacts of that small difference are actually big:
The impacts are what policy makers are responsible for. And this infographic does not show what impacts are likely at 3°C or 4°C. We can attribute this lack of information to the aforementioned excessive focus on 1.5°C and 2°C by the research community. It will be hard to decide on climate policy moving forward if we are not appropriately informed about the risks that today’s decisions are locking in.