The comprehensive new report from the United Nations Intergovernmental Panel on Climate Change offers some optimism if we continue to control emissions. Under one scenario, global temperatures could rise above 1.5°C by mid-century and then fall back by the end of the century. According to the panel, such a relatively short period above 1.5°C may not lead to the worst consequences. However, the panel says that the 1.5°C mark could be reached by 2040 or even earlier, possibly around 2025. The UN climate conference in November must show an unprecedented commitment to actively reduce our emissions and to offset some of the emissions we cannot reduce. (NASA, Satellite image)