Study: 2018 was the 4th-warmest ever, and this year will be hotter

Global temperatures in 2018 were the fourth-warmest on record, continuing the planet's long-term warming trends, according to a California-based research group's new report.

Human activities are the "direct cause" of rapid warming trends in recent decades and it's only going to get warmer, says Berkeley Earth, a nonprofit research group that has produced annual global temperature analysis since 2013.

The researchers predict 2019 will become the second-warmest year since 1850, the first year for which detailed records are available.

Ocean surface temperatures were extraordinarily warm, too — the fifth-warmest on record, the researchers found.

"As can be expected from global warming caused by greenhouse gases, the temperature increase over the globe is broadly distributed, affecting nearly all land and ocean areas," their report said.

Twenty-nine countries had their warmest year ever in 2018, Berkeley Earth found, and Antarctica was hotter than ever observed.

Typically, NASA and the National Oceanic and Atmospheric Administration conduct annual climate analysis like the Berkeley Earth one.

Berkeley Earth, though, noted the federal government shutdown has halted this year's reports and made some weather data unavailable. Still, the researchers were able to find the information they needed from other sources unaffected by the shutdown.