thirteen - 12:58 am on Jun 25, 2011 (gmt 0)
They are correct. That particular title format is geared toward Bing/Yahoo search engine. For Google, you have a little more leeway. Bing/Yahoo has told webmasters what is the preferred Title format and your SEO consultants delivered it that way.
Your original title "10 Myths About Global Warming" can be kept. Move it to Description meta tag. It fits in with SEO guidelines for copy writing the description snippet. You can still keep the previous work that you have done so no one's feelings get hurt.
If you don't want to modify the webpages that are already getting traffic then tell them which pages they should be focused on. They are going after the low lying fruits. Nothing is wrong with that. You see results much faster, so you can decide whether if SEO is right for you.
Since they work for you, you can task them with more difficult webpages. To be fair with your SEO consultants, give them webpages that has excellent article content but poor search engine visibility ranking. That is something they can work with. Otherwise, you are tasking them to write contents for you which is a more time consuming job.