There are serious skeptics. Like you say nobody really disagrees with 1) humans release more c02 and 2) more c02 = warming via greenhouse.<p>But that isn&#x27;t the entire global warming theory.<p>There are many feedback effects that occur. Like warming -&gt; melting ice -&gt; water vapor from condensation -&gt; water vapor is a greenhouse gas -&gt; more heat<p>But there are negative feedback effects too. Like warming -&gt; melting ice -&gt; less reflection of sun -&gt; less heat<p>So many people are pushing theories with high feedback multiples. Some people are pushing theories with high negative feedback.<p>Depending on how you model the feedbacks--Climate change can either be a small issue with a degrees or two warming or a mass extinction event with 5 degree C warming.<p>The problem is it is very hard to test the models.