"Naturally fueled" is Bob's code word for "magic". Bob is one of the utter nutters. He thinks that the physics of the greenhouse effect is a hypothesis and he thinks it doesn't hold up. These days he's in the minority of deniers.
Most fake sceptics these days accept that there are such things as greenhouse gases and that the world is warming. They'll argue various things like how much the world is warming and what the future climates will be like, but they realise they'd look pretty stupid if they denied any warming at all.
Bob Tisdale looks pretty stupid.
Here is a chart showing the ocean heat content down only as far as 700 metres, including the Indian Ocean that Bob Tisdale doesn't want his readers to know about:

Data Source:
NOAA/NODC
The heat accumulating in the different oceans is added together to get the total heat accumulating in all the oceans. The chart above shows just how much the system is heating up.
The chart below shows the top two kilometres of ocean. It's accumulating more and more heat. The heat from the top 700 metres is heating the layers below. Bob doesn't want his readers to know that.
HotWhopper Bob Tisdale rejects the greenhouse effect again