Why does the subject of climate change cause such robust debates? The answer has to do with how robust the science is.
Science has many branches, but are conclusions reached by each branch equally reliable? The most reliable science is done in laboratories utilizing materials that can be subject to experimental processes. The historical sciences do not fall into this category.
The less reliable the science, the more robust are the debates. The most heated debates occur on topics such as evolution, the big-bang theory and climate change. These are all topics within the historical sciences.
The discussions are passionate because the data is inherently limited. We simply cannot put our climate into a laboratory and subject it to experimental processes over eons of time. Thus, the historical sciences must utilize speculation in order to fill in the gaps in knowledge.
Speculation is defined as the forming of a theory or conjecture without firm evidence.
Since the data is inherently inconclusive, the debates are robust as we each try to convince each other whose speculation is most accurate. These debates are as much philosophical as they are scientific.
Problems occur when scientists over-state their conclusions. Too often, the historical scientists convince themselves (and us) that their conclusions are on par with experimental science conclusions.
One case in point is the dooms-day scenarios put forth over the past 50 years (none of which have come true) by climate scientists. Check them out for yourself.
We absolutely need to be good stewards of the extraordinary planet we live on. This should include scientific research. But spinning our wheels trying to avoid far-fetched catastrophes as if man is some form of cancer on Earth is a waste of energy.