Before you may the title change, what keywords were people using that actually found that page in google? (you can look that up with google analytics.)
I think that part of your dilemma is trying to figure out what you are trying to rank for.
If you are trying to rank for the words "global warming" (I know this is just an example), then the second example (provided by your SEO company), SHOULD be better.
But you have to look at how much competition there is for that keyword. If there is a LOT, then there is probably no way that you are going to rank for it no matter which title you use. (You will have to do a LOT more than just have an SEO specific title.)
However, if there are a lot of people searching specifically for myths about global warming, and you think you can rank well for it, then 10 Myths About Global Warming is probably a better title.
Let me give you an example: I have a page with the title Widgets Information and Resources. It gets lots of traffic.
But I just realized (after going through google analytics), that very few people who find the page through the keywords "widgets information" or "widgets resources."
Instead, most of the people who find it in google find in when searching for "widgets 101"
So I have changed the title to "Widgets 101: Basic Information About Widgets"
We will see how it goes since I just made it a day or two ago. But my decision was based on the fact that I was ranking nowhere for the keywords "Widgets information" and nowhere for "widgets resources," so I think that if people are already finding my site through "widgets 101" then the title and meta description of the page should reflect that.
Hope this helps.