Thanks for your note and absolutely not! The earth is at its hottest point in over 11,000 years.
Your client believes a rumor from the 1970s, one that won’t die apparently. It was dismissed, debunked, defrocked, and deblorgged decades ago, but has resurfaced as a rather brilliant right-wing political talking point.
97% of climate scientists agree the earth is warming. This is the highest agreement in any of the sciences in all of history. Second, the vast majority of scientists in the 1970s agreed global warming was occurring, that humans are causing it by emitting greenhouse gases, and that the earth is in big, big trouble.
Back in 2005, climate scientists at Real Climate took the time to discuss the origins of the rumor, show who restarted it, and describe why it’s completely false. You an read their post, here.
In 2008, the American Meteorological Society published a special article on this myth. It’s a great read, very short. It describes the history of the myth (it also gives a glimpse at how scientists suck at PR).
Lastly, Skeptical Science ranks it as the 11th most discussed myth. They published a simplified, easy to read summary of the myth called: “What were climate scientists predicting in the 1970s?”, which shows that scientists back then were very worried about warming.
At the end of the day, your client is acting as proxy for the fossil fuel industry. This may sound crazy, but his/her’s real argument is that oil and gas should not be regulated, that they should be able to pollute without regulations. People who argue that that the world is cooling, instead of warming, are really saying that there is no need to regulate pollution or emissions.
What’s even more bizarre is that they may not even realize this.
Naomi Oreskes discusses how this happened in her book, Merchants of Doubt, which shows that oil and gas industries hired the same public relations experts that defended the tobacco industry in the 80s. Recall that the tobacco industry - and the politicians they donated to - denied that cigarettes caused cancer (seriously), and they successfully perpetuated that myth for decades.
And that, my friend, is how an industry and politicians manipulate public opinion.