In the nine years since private equity and venture capital investments into sustainable technologies last crossed the $6 billion threshold, the problems caused by global carbon emissions have only intensified.

Now, as the world confronts the reality that there’s not much time left to reverse course on carbon emissions and the impact they will have on life on earth, both corporate and private investors are once again stepping up their commitments to startups in the space.

In 2018, global venture capital investment into startups focused on sustainability jumped 127 percent, to $9.2 billion, the highest since 2010, according to a January report from Bloomberg New Energy Finance. Powering that boost was a $1.1 billion investment in the smart window maker, View, and another $795 million for Chinese electric vehicle firm Youxia Motors. In fact, there were no fewer than eight VC/PE financings of Chinese EV specialist companies in 2018, totaling some $3.3 billion.

That stark assessment is coming from more corners of the scientific community, and the reality of the danger is being emphasized by politicians and concerned citizens around the globe.

The simple truth is that things are getting worse. And for the past two years, emissions have been increasing as countries continue to use oil and gas and coal to fuel economic growth, even as the global community realizes that carbon emissions are an increasing threat.

A recent assessment by the U.S. government put the cost of climate change caused by carbon emissions at $500 billion annually by the end of the century. And the financial toll doesn’t begin to assess the cost to the quality of human life and the potential lives that will be lost because of climate-related disasters.

This isn’t the first time the world has realized the threat climate change poses. It’s not even the second. Back in 1979 — and throughout the next decade — the U.S. grappled with how to craft an appropriate response to the coming climate-related crisis. Perhaps unsurprisingly, the government failed, and the issue of imminent climate disaster was set aside.

Former Vice President Al Gore picked up the thread in the mid-2000s in the wake of his defeat to the Connecticut Yankee turned Texas oilman George W. Bush in the contested 2000 presidential election. Through advocacy work and the popular climate-focused documentary “An Inconvenient Truth,” Gore was able to proselytize among a group of technocrats looking for the next big thing in the wake of the internet explosion that had transformed professional and personal lives.

Venture capital investors flocked to invest in renewable technologies — from biofuels to new solar energy generating technologies to new battery chemistries and beyond.

Over the next seven years billion-dollar companies would rise and fall on the back of speculative investment in the promise of a cleaner energy future that would disrupt the oil industry and turn billionaires into multi-billionaires — all while saving the world.

It didn’t work out.

Problems with scaling technologies beyond a controlled laboratory setting; global economic pressures wrought by an explosion of manufacturing capacity in countries like China; and the hubris of investors who thought that their investment acumen in picking winners of the information age could work just as well in centuries-old industries like oil and gas, or electricity, found themselves floundering in complicated, regulated markets with deep-pocketed incumbents and entrenched interests in promoting the status quo.

In the process, investors lost hundreds of millions of dollars in the U.S. alone, and destabilized some of the oldest firms in the investment industry.

Now, companies and investors are returning to the market in a major way. Some of the largest businesses in the food and agriculture industry are investing in new companies that are developing protein replacements and novel cultivation technologies; utilities are investing more heavily in smart grid technologies as electrification and microgrids become more real; automakers and battery manufacturers are backing new energy storage technologies; and frontier investors are backing companies tackling everything from biologically based chemical manufacturing to new construction technologies for smart homes and cities, to new kinds of nuclear power that could transform how the world conceives of energy abundance (along with geo-engineering tech to remove carbon from the atmosphere).

“In the last few years, the number of technologies ripe for investment has expanded dramatically,” Ravi Manghani, research director for energy storage at Wood Mackenzie, an energy research and consultancy firm, told CNBC in March. “It’s no longer just three or four technology verticals.”

While none of these technological advancements are a guaranteed solution to the threats carbon emissions pose, or are surefire commercially viable businesses, the fact that investors are once again looking at sustainability as a viable investment thesis — capable of producing multiple billion-dollar businesses — is a good step forward.

Any plan to address decarbonization has to confront industries as diverse as agriculture, construction, transportation, chemicals and consumer goods from clothes to chemicals.

Failure to confront these challenges would be catastrophic. Even if global warming is restricted to just the 2 degree Celsius target set at the Paris climate agreement, that could mean the extinction of the world’s tropical reefs and several meters of sea-level rise, as The New York Times reported last August. Already the impacts of climate change have meant tens of billions of dollars in damage for the U.S. in 2018 alone.

“The era of incrementalism on climate change is over,” said Massachusetts Senator Ed Markey, one of the architects of the “Green New Deal” legislation, in an interview with Vox. “We are now in the era of the Green New Deal. It’s not going away. It is creating an incentive for governors to do more, for mayors to do more, for companies to do more. The polling says it has political legs that will drive it right into the election of 2020, and when that cycle is done, I think we’re going to see a much greater capacity for us to take the kind of action that we need.”