To preserve a "livable planet," the Earth can't warm more than 1.5 degrees Celsius above pre-industrial levels, the United Nations warns.

Failure to maintain that level could lead to several catastrophes, including increased droughts and weather-related disasters, more heat-related illnesses and deaths, and less food and more poverty, according to NASA.

To avert the looming tribulations and limit global temperature increases, 194 member states and the European Union in 2016 signed the U.N. Paris Agreement, a legally binding international treaty with a goal to "substantially reduce global greenhouse gas emissions."

After the agreement, global spending on climate-related projects increased exponentially.

In 2021 and 2022, the world's taxpayers spent, on average, $1.3 trillion on such projects each year, according to the nonprofit advisory group Climate Policy Initiative.

That's more than double the spending rate in 2019 and 2020, which came in at $653 billion per year, and it's significantly up from the $364 billion per year in 2011 and 2012, the report found.

Despite the money pouring in, the National Oceanic and Atmospheric Administration (NOAA) reported that 2023 was the hottest year on record.

NOAA's climate monitoring stations found that the Earth's average land and ocean surface temperature in 2023 was 1.35 degrees Celsius above the pre-industrial average.