World must sharply cut emissions by 2030 to meet Paris climate goals

The odds of calamitous climate events, from collapsing polar ice sheets and the ensuing sharp rises in sea levels to deadly heat waves, increases dramatically if the world exceeds the Paris Climate Agreement's temperature targets.

Why it matters: In order to have a decent chance of meeting the agreement's most ambitious temperature target — holding warming to 1.5 °C above preindustrial levels — greenhouse gas emissions need to be sharply reduced before 2030.

The big picture: With the world hurtling toward potentially catastrophic levels of warming, a Herculean effort involving a slew of clean energy technologies is needed to pivot to a different emissions path.

How it works: If the world waits until the 2030s to bend the emissions curve downward, the pace of cuts required to meet the agreement's temperature targets would likely be too expensive, and may be technologically impossible.

What they're saying: John Kerry, Biden's climate envoy, told reporters Saturday that committing to reach net-zero emissions in 2050 is insufficient.

• "Many people are focusing on 2050 net this, and 2060 net that. That’s good, and we’re happy to have people do it, but not to the exclusion of being super-focused on this decade," Kerry said in Seoul.
• "If we don’t do what we need to do between 2020 and 2030, those other things become impossible."