Just last week, we reported that Earth's atmospheric carbon levels passed 400 parts per million and probably won't ever return to more environment-friendly levels. Now, as is basically always the case, we have more bad news about climate change.

This week's downer is from former senior NASA climate scientist James Hansen, who has long been one of the premier researchers of climate change. Along with 11 other experts, Hansen submitted a paper, titled "Young People’s Burden: Requirement of Negative CO2 Emissions," which states that temperatures in 2016 will likely be 1.25 degrees Celsius above pre-industrial times. The paper explains, "The rapid rise of global temperature that began about 1975 continues at a mean rate of about 0.18°C/decade."

In fact, thanks to climate change, the global temperature hasn't been this lit in 115,000 years, according to the Guardian. Hansen, who is widely credited with raising global awareness about climate change, told the Guardian that the "science is crystal clear," and that we must "phase out emissions over the next few decades." The paper says that if the "rapid phasedown of fossil fuel emissions begins soon," we should be able to reduce CO2 levels with better agricultural and forestry practices. If we could pull that off, the paper says we can limit and minimize any irreversible damage.

For that to happen, though, Hansen says we need "substantial actions by Congress and the executive branch." But that strategy hasn't really worked out. Therefore, Hansen explains, "we need the courts to apply pressure, as they did with civil rights." If that doesn't happen, the "continued high fossil fuel emissions by the current generation would place a burden on young people to undertake massive technological CO2 extraction, if they are to limit climate change," the paper says.

That sure won't be cheap, and the paper estimates it could cost of hundreds of trillions of dollars this century. The paper states that continuing at our current levels of emissions "unarguably sentences young people to either a massive, possibly implausible cleanup or growing deleterious climate impacts or both."

As the paper points out, while we've known for decades that trouble comes with climate change, global fossil fuel emissions still continues at a problematically high rate. Part of the problem is that many still don't believe human actions affect climate change. Despite the fact that the U.S. has the highest carbon emissions per capita, Americans are among the least concerned in the world about climate change, according to the Pew Research Center.

Americans' concern about climate change is also split between political parties. Republicans are much less likely to worry about climate change, and their nominee has claimed that climate change is a hoax made up by the Chinese:

Welp, Earth was nice while it lasted.