The HAPPI simulations, which target specific warming levels of 1.5 ◦C and 2.0 ◦C following the Paris Agreement, project that fire weather conditions will be more extreme worldwide regardless of the warming level. However, suppressing the 0.5 ◦C additional warming could reduce climate-driven extreme fire activities globally, except for a few areas that seem to reach their peak risk level at an earlier warming state (before 1.5 ◦C). HAPPI experiments include a large number of ensembles for statistical significance.
In areas of accelerated fire hazard, including Australia, Indonesia, and the southwest USA, an even stricter target to reduce climate-warming would be required. Although climate increasingly may be reassuming a role as the dominant influence on fire, wildfires are not merely driven by fire weather but also vegetation changes, fuel loads, and ignition sources (e.g. lightning activity).
When it comes to the conditions that make wildfires more likely, a little bit of warming goes a long way, but this is troubling because it is quite unlikely that we will only be experiencing a little bit of warming. While it may seem that just half a degree of additional warming would have little impact on people and ecosystems, the scientists’ analyses found it can make a big difference. The study indicates that the difference would be felt in increased fire severity and frequency and a 2-degree rise adds significantly more danger than an increase of 1.5 degree of warming, a rate referred to in the paper as half a degree of additional warming.