We have 12 years to limit climate change catastrophe, warns UN | Environment | Oct 2018 The Guardian

Carbon pollution would have to be cut by 45% by 2030 – compared with a 20% cut under the 2C pathway – and come down to zero by 2050, compared with 2075 for 2C. This would require carbon prices that are three to four times higher than for a 2C target. But the costs of doing nothing would be far higher.:

Source: We have 12 years to limit climate change catastrophe, warns UN | Environment | The Guardian