Originally Published in the Carbon Brief Dr Karsten Haustein and Dr Friederike Otto are scientists at the University of Oxford’s Environmental Change Institute; Zeke Hausfather is the US analyst for Carbon Brief; Peter Jacobs is a PhD student at George Mason University. The role of variability due to natural ocean cycles in global warming is a long-standing debate in climate science. The scientific community overwhelmingly agrees that human activities are responsible for the observed increase in temperatures for the last half-century. However, the relative influences of natural…