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。

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

我猜是b) 5000亿吨。

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。

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%。

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？

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。

But these alone can't get  us to the gigatonne levels of carbon capturing that we have to achieve.

但仅靠这些并不能使我们达到我们必须达到的十亿吨碳捕获水平。

If they're focused on the parts of the Arctic that are richest in carbon and most at risk, then it can have an impact comparable to a gigatonne of carbon dioxide per year.

如果他们专注于碳含量最丰富且风险最大的北极地区，那么它所产生的影响相当于每年排放 10 亿吨二氧化碳。

So usually what I tell people is half a gigatonne and if you need a spreadsheet to show me how you get to half a gigatonne, never mind, right?

所以通常我告诉人们的是半十亿吨， 如果你需要一个电子表格来告诉我你是如何达到半千兆吨的，没关系，对吧？