This story is the first article of a two-part Mongabay mini-series exploring possible climate futures. Read Part One. Humanity stands at a critical juncture in the climate emergency: As countries worldwide prepare to submit their climate commitments for the next decade, scientists report mounting evidence that we are very close to breaching the 1.5° Celsius limit set by the Paris Agreement 10 years ago. Beyond 1.5°C (2.7° Fahrenheit), we increasingly risk crossing climate tipping points, with dire consequences. This story asks top climatologists and Earth system scientists what climate futures may await us if we fail to decarbonize quickly enough, what the consequences might be for humanity and how climate action could alter the dangerous trajectory we’re on. The concentration of CO2 in the atmosphere reached 422 parts per million in 2024 — 52% above preindustrial levels. Global greenhouse gas emissions are yet to peak, and our remaining carbon budget to limit warming to 1.5°C is expected to be used up by 2030. Image courtesy of the Global Carbon Budget. Last chance to change course For global average temperatures to stabilize at 1.5°C above preindustrial levels and avoid climate catastrophe, humanity must make substantial greenhouse gas emissions cuts of roughly 43% before 2030 and achieve net-zero emissions by 2050, according to the most recent U.N. Intergovernmental Panel on Climate Change (IPCC) report. However, progress on climate action has stagnated as the world grapples with war, political instability, significant backsliding by the U.S. on climate action and escalating extreme weather events.…This article was originally published on Mongabay