气候变化挑战下如何实现“净零排放”

许多政府正在试图减少温室气体排放，以应对气候变化。但我们能否实现不产生任何多余排放的目标？

We are all aware of the effect greenhouse gas emissions is having on our planet and the efforts needed to tackle climate change. Most of us are doing our bit to minimise our impact on the environment, but despite our collective effort, are we doing enough to achieve net zero by 2050?

Net zero means not adding to the amount of greenhouse gases in the atmosphere. Many countries are doing their bit by changing how they generate and use power, thereby cutting carbon dioxide output. And they announced what further steps they were going to take at the recent COP26 summit in Glasgow.

In the UK, the government has been setting out its plans to achieve net zero by 2050. It's recently announced an end date for the sale of gas boilers, which are used for heating homes. The idea is to replace them with heat pumps. It's offering homeowners grants of up to £5,000 to get them installed. Another initiative in the UK is a big push towards electric vehicles. There are to be financial incentives for car manufacturers, and more charging points are to be installed in streets. And there's to be a ban on the sale of new petrol and diesel cars by 2030.

But not all emissions can be reduced to zero, so those remaining will have to be compensated for, or offset. One way to do this is to plant thousands of trees, which are good at absorbing carbon dioxide. The UK government has pledged to plant 30,000 hectares of trees a year by 2025. There are other ideas too, but what's certain is this will cost money. The CBI's Tom Thackray told the BBC that “those costs have to be weighed up against the cost of inaction.”

Whether the UK, or anyone else, reaches net zero remains to be seen. And there's some doubt about how this can be accurately measured anyway. But it's generally recognised that a global effort is needed to tackle climate change. Therefore, net zero targets only make sense if every other country is moving in the same direction.