This week, pinning down China's immense emissions.

Chinese cumulative emissions actually 12 gigatong less than previously understand.

And 10 years after Hurricane Katrina, what can the rest of the world learn?

Before other parts of the world get affected in such a devastating way, I would like to see

some thinking about how do we make coastal areas more resilient.

Plus, can genes leap sideways into ourselves?

This is the Nature Podcast for August 20, 2015.

I'm Adam Levy.

And I'm Kerry Smith.

Talking about the change without mentioning China is like talking about pizza without mentioning Italy. China's been the world's largest

emitter of CO2 for almost a decade and its emissions have kept rising, mostly thanks to huge increases

in the burning of coal. Later this year, policymakers from around the world will meet in Paris

to make a climate deal. Before the meeting, countries are pledging targets to curb their emissions.

But that implies we know what these emissions are. And for China, we don't.

We know their emissions are big, but there is huge uncertainty in just how big.

Now, an international group of researchers have got together to try to arrive at a definitive answer.

I spoke with Dabo Guan from the University of East Anglia to find out what the team learned.

To our best knowledge, and also we can say this is the best knowledge in the whole research

field, we estimate Chinese emissions from 1990s to 2013.

And over the roughly 23 years, their emissions cumulatively is 12 gigatong less than previously estimated by the IPCC.

So it's about 15% of the annual Chinese emissions.

15% sounds like, you know, a really big amount,

...