In bleak report, U.N. says drastic action is only way to avoid worst effects of climate change

The world has squandered so much time mustering the action necessary to combat climate change that rapid, unprecedented cuts in greenhouse gas emissions offer the only hope of averting an ever-intensifying cascade of consequences, according to new findings from the United Nations. Already, the past year has brought devastating hurricanes, relentless wildfires and crippling heat waves, prompting millions of protesters to take to the streets to demand more attention to a problem that seems increasingly urgent. Amid that growing pressure to act, Tuesday’s U.N. report offers a grim assessment of how off-track the world remains. Global temperatures are on pace to rise as much as 3.9 degrees Celsius (7 degrees Fahrenheit) by the end of the century, according to the United Nations’ annual “emissions gap” report, which assesses the difference between the world’s current path and the changes needed to meet the goals of the 2015 Paris climate accord. As part of that deal, world leaders agreed to hold warming to “well below” 2 degrees Celsius compared with preindustrial levels; the current trajectory is nearly twice that. Should that pace continue, scientists say, the result could be widespread, catastrophic effects: Coral reefs, already dying in some places, would probably dissolve in increasingly acidic oceans. Some coastal cities, already wrestling with flooding, would be constantly inundated by rising seas. In much of the world, severe heat, already intense, could become unbearable. Tuesday’s report, which is viewed as the benchmark of the world’s progress in meeting its climate goals, underscores how the pledges that nations made years ago in Paris are woefully inadequate to achieving the goals of the accord. To hold warming to “well below” 2 degrees Celsius, the authors found that countries would need to triple the ambition of their current promises. To hit the more ambitious target of no more than 1.5 degrees of warming, they found, nations would need to ramp up their pledges fivefold...MORE