Is it a) 450 gigatonnes, b) 500 gigatonnes, or c) 550 gigatonnes?

是 A. 450 千兆吨，B.500 千兆吨，还是 C. 550 千兆吨？

No they don't. They emit about 0.25 gigatonnes annually. That's less than one percent as

在长期观测下我们发现大气中碳十三的浓度正在减少。

Today, that figure is already down to less than 350 gigatonnes.

今天，这一数字已经降到了3500亿吨。

I'll take a guess at b) 500 gigatonnes.

我猜是b) 5000亿吨。

Yes, you asked me how many gigatonnes of Greenland's ice sheet are now melting every year.

是的，你问我格陵兰岛现在每年融化多少冰原。

So my quiz question is this: how many gigatonnes of ice are now melting into the ocean every year?

每年有多少海冰融入海洋？

However, last year coal-fired electricity emitted more than ten gigatonnes of carbon dioxide for the first time, 30% of the world's total.

然而，去年燃煤发电首次排放了超过100亿吨的二氧化碳，占世界总量的30%。

So overall, they found discrepency of three gigatonnes which in lams and terms as 10% of the global emissions in 2013.

总之，他们发现了中国30亿吨的差额，这相当于2013年全球排放量的10%。

If nothing is done, pollution from two- and three-wheeled vehicles in Africa will hit 1.7 gigatonnes of emissions every year, according to our estimates.

如果什么都不做，根据我们的估计，两、三轮车辆的污染排放量将会达到每年十七亿吨。