Sucking CO2 out of the air is vital to preventing climate change, UN warns 

Technology that sucks carbon dioxide out of the atmosphere will be essential to prevent climate change, a UN report concludes today.

Even a wholesale switch to renewable energy and everyone giving up driving and flying may no longer be enough to avoid a crisis.

Global warming is already 1.1C above pre-industrial levels and scientists warn of irreversible harm if this exceeds 1.5C.

The report, by the United Nations’ Intergovernmental Panel on Climate Change (IPCC), says an urgent shift from fossil fuels is needed for any chance of keeping warming below this level. 

Extracts from a draft of the report’s summary said: ‘Carbon dioxide removal is necessary to achieve net-zero greenhouse gas emissions globally and nationally.’

If ‘negative emission’ technologies fulfil their potential, it said, they could even enable a reversal of global warming.

But the report, commissioned and endorsed by 195 governments, acknowledges the only ‘negative emissions’ strategy now in deployment is tree planting.

Scientists are working on other techniques, such as direct air capture, where fans extract carbon dioxide and store it underground or convert it into jet fuel.

Yet the 19 direct air capture plants in operation are capturing only 10,000 tons of CO2 a year, compared with 36billion tons emitted annually.

Other techniques include ocean fertilisation, a theoretical approach in which nutrients are added to the sea to stimulate phytoplankton – microscopic organisms – that take up CO2, and enhanced weathering, in which crushed volcanic rock is spread over farmland to boost the soil’s ability to absorb CO2.

However, campaigners believe that a focus on the negative emissions technology provides a licence to ‘burn now, worry later’.

Even a wholesale switch to renewable energy and everyone giving up driving and flying may no longer be enough to avoid a crisis