Scariest part of climate change isn’t what we know, but what we don’t

7 08 2015
image-20150731-18728-1ntffbr

© Nick Kim

My good friend and tropical conservation rockstar, Bill Laurancejust emailed me and asked if I could repost his recent The Conversation article here on ConservationBytes.com.

He said:

It’s going completely viral (26,000 reads so far) in just three days. It’s been republished in The Ecologist, I Fucking Love Science, and several other big media outlets.

Several non-scientists have said it really helped them to understand what’s known versus unknown in climate-change research—which was helpful because they feel pummelled by all the research and draconian stuff that gets reported and have problems parsing out what’s likely versus speculative.

With an introduction like that, you’ll just have to read it!

“It’s tough to make predictions, especially about the future”: so goes a Danish proverb attributed variously to baseball coach Yogi Berra and physicist Niels Bohr. Yet some things are so important — such as projecting the future impacts of climate change on the environment — that we obviously must try.

An Australian study published last week predicts that some rainforest plants could see their ranges reduced 95% by 2080. How can we make sense of that given the plethora of climate predictions?

In a 2002 press briefing, Donald Rumsfeld, President George W. Bush’s Secretary of Defence, distinguished among different kinds of uncertainty: things we know, things we know we don’t know, and things we don’t know we don’t know. Though derided at the time for playing word games, Rumsfeld was actually making a good point: it’s vital to be clear about what we’re unclear about.

So here’s my attempt to summarise what we think we know, don’t know, and things that could surprise us about climate change and the environment.

Things we think we know

We know that carbon dioxide levels in the atmosphere have risen markedly in the last two centuries, especially in recent decades, and the Earth is getting warmer. Furthermore, 2014 was the hottest year ever recorded. That’s consistent with what we’d expect from the greenhouse effect. Read the rest of this entry »