Recent events indicate Earth's climate entered uncharted territory

"Heat sets the pace of our climate in so many ways … it's never just the heat," said Kim Cobb, a climate scientist at Brown University.

Dying coral reefs, more intense Nor'easters and the wildfire smoke that choked much of North America this summer are among the many other signals of climate distress.

"The increasing heating of our planet caused by fossil fuel use is not unexpected, but it is dangerous for us humans and for the ecosystems we depend on. We need to stop it, fast," said Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research.

Some other recent "firsts" and events that indicate climate change entered uncharted territory:

Wildfires raging across Canada have already broken records for total area burned, the number of people forced to evacuate their homes and the cost of fighting the blazes, and the fire season is only halfway finished, officials said Thursday.

Smoke originating from those fires brought dangerous air quality levels to eastern North America. The high levels of wildfire smoke have become familiar on the West Coast, but scientists say climate change will make wildfires and smoke more likely and intense, and the East Coast will see more of it.

Ryan Allen, a professor of health sciences at Simon Fraser University in Burnaby, British Columbia, said the fine particles found in fire smoke have the ability to travel long distances and can penetrate deep into airways.

“When you’re emitting large amounts of fire smoke into the air, and that smoke is reaching populated areas, there will be health effects,” he said. 

Most of the planet is covered by oceans, which absorbed 90% of the recent warming caused by gases such as carbon dioxide and methane. In April, global ocean temperature soared to 69.98 degrees Fahrenheit, which was attributed to the combination of greenhouse gas emissions and the early El Nino formation.

Newly published data from the Copernicus Climate Change Service documented "exceptionally warm" ocean temperatures in the North Atlantic with "extreme" marine heat waves near Ireland, the U.K. and in the Baltic Sea.

The current El Nino — a period of warming Pacific Ocean waters — formed a month or two earlier than usual, replacing a La Nina that cooled Pacific waters and served as a damper on global temperatures. This means the El Nino will have more time than usual to strengthen. The World Meteorological Organization predicts there is a 98% chance at least one of the next five years will be the warmest on record, beating 2016, when an exceptionally strong El Nino was present.

Scientists are watching Antarctic sea ice shrink to record lows. The 4.5 million square miles covered by the sheet on June 27 was nearly 1 million square miles less than average for the same date for the 1981-2010 period, according to the National Snow and Ice Data Center.

Put another way, an area almost four times the size of Texas was gone from the ice sheet.