I find it interesting how many want to disregard any input from scientists working in the oil industry, but won't even consider a potential bias for environmentalists or academics who are highly invested in supporting global warming and "man made" climate change.
Unfortunately, this speaks to a lack of understanding of how science works. The livelihood of industry scientists relies on them doing their job for their company. In the case of petroleum engineers, their job is to produce oil. If these guys start telling their bosses they need to produce less oil, they won't remain employed.
On the other hand, academic scientists have no vested interest in supporting a particular topic. In fact, when we publish our work, we are required to sign conflict of interest statements to indicate any potential outside influences on the work. Our paychecks come from the University. If we receive a federal grant, we can take "summer salary" from the grant, which a maximum of the two months we don't get paid by our Universities (I usually take one month salary from my grants and work one month for free). Summer salary is also capped, so that if you receive multiple grants, you can't double dip. If an academic scientist publishes papers that support climate change, they get paid "x" amount. If they publish papers that oppose climate change, they receive the same paycheck. There is no financial interest that academic scientists receive from supporting climate change. The beauty of academic science is that scientist are free to let the data inform their understanding of the world. It is a critical evaluation of tens of thousands of studies across different disciplines, all supporting climate change, that has led most academic scientists to support anthropogenically induced climate change.