THE SYSTEM OF ocean currents that bring warm water to the north Atlantic Ocean is likely to collapse by the middle of the century if greenhouse gas emissions are not reduced, a new study has found. Researchers in Denmark studying the Atlantic meridional overturning circulation (AMOC) expect it to collapse this century under current projections of future emissions. The study, published today in scientific journal Nature, expects that the AMOC will collapse some time between 2025 and 2095, with “high confidence” that it will happen as soon as the middle of the century. The AMOC regulates how heat moves from...