One of the many side events here at the climate conference was a session on the loss and damage suffered by the poorest and most vulnerable communities as a result of the effects of climate change.
It was held jointly by the Climate Justice Programme (CJP) and the Heinrich Böll Foundation, who propose to establish a global “carbon levy” on all fossil fuel extraction, to be paid into an international loss and damage mechanism to help those communities facing the worst impacts of climate change.
There have also been side events on climate displacement, to discuss climate change-induced migration – including forced displacement – and human mobility.
What was not mentioned at any of these events is that both the carbon levy and the climate displacement proposals (which are not matters that would ordinarily be considered together) face huge issues of causation and attribution – matters that are crucial in addressing the climate change problem.
This is especially so for climate displacement.
At the loss and damage side event, the CJP pointed out that the single biggest cause of climate change is burning fossil fuels, and that the “carbon majors” – who include big coal, oil and gas – have extracted fossil fuels responsible for roughly two-thirds of climate change pollution.
It further argued that poor and vulnerable communities are paying for loss and damage with their lives, homes and livelihoods, while the carbon majors “make huge profits from selling the products responsible for causing climate change”.
Climate displacement had already been examined at an event on December 1, which discussed the importance of social science research for understanding climate change-induced migration. It was argued that the relationship between climate change and migration was not straightforward but, rather, is multifaceted and touches on virtually all aspects of life.
And at the weekend, yet another event, organized by a large number of non-government organisations from Bangladesh and other least-developed countries, argued for the creation of a new UN protocol for loss and damage, based on the principle of “common but differentiated responsibilities” of different nations for climate change.
An important issue associated with all of the these proposals is the extent to which climate change causes the event that gives rise to the loss and damage or the displacement. It is not possible at present for science to determine whether a particular environmental event was caused by climate change. It is possible, however, to identify certain phenomena and trends as consistent with climate change.
Another issue is the extent to which humans contribute to particular climate change events. Science can determine neither whether a particular environmental event was caused by climate change, nor the extent to which humans contribute to specific climate change events.
However, it has also been argued that science can determine the likelihood that humans have “contributed to a type of disruption”.
This moves us on to the issue of attribution. As Carbon Brief reported earlier this year, attribution studies look at each individual event alone to see how climate change may have made that event stronger or more likely.
But a new paper in Nature argues that the methods used in these studies tend to underestimate the influence of climate change, and suggests a new approach to identify the “true likelihood of human influence”.
This paper says that a better approach is one “which asks why such extremes unfold the way they do”. Specifically, it suggests that it is more useful to regard the weather event (or other incident) as being largely unaffected by climate change, and question whether known changes in the climate system’s thermodynamic state affected the impact of the particular event.
It’s complex science that underpins an even more complex issue.
Rebecca Johnston contributed reporting for this blog post.