Ice collapsing into the water at Perito Moreno Glacier in Los Glaciares National Park, ArgentinaR.M. Nunes/AlamyEven a few years delay in reaching net-zero emissions will have repercussions for hundreds or even thousands of years, leading to warmer oceans, more extensive ice loss in Antarctica and higher temperatures around the world.Nations around the world have collectively promised to prevent more than 2C of global warming, a goal that can only be achieved by reaching net-zero emissions effectively ending almost all human-caused greenhouse gas emissions before the end of the century. But once that hugely challenging goal