Climate change has global impacts, but hits poor and vulnerable communities first and worst. The 47 Least Developed Countries (LDCs) are at a disproportionately high risk of adverse consequences with global warming of 1.5°C and beyond. LDCs contribute the least to global warming. But over the last 50 years, 69% of worldwide deaths caused by climate-related disasters were in LDCs. Now, a rapid global response is urgently needed. All countries must do their fair share to rapidly reduce emissions and provide adequate support to the poorest and most vulnerable. Significantly more climate finance needs to be provided by developed countries. Nationally Determined Contributions to reduce emissions must become vastly more ambitious, based on each country’s level of responsibility for causing climate change and its capacity to address the global crisis.