Nicholas Stern, one of the world’s most influential economists, has come out with a new report showing that the future costs of climate change have been incredibly underestimated.

The report, Endogenous growth, convexity of damages and climate risk, indicates it is even more important than previously thought that politicians quickly and aggressively stop unchecked climate change caused by man-made carbon dioxide emissions.

Stern, a professor at the Grantham Institute at the London School of Economics, and his co-author Simon Dietz found that the current economic models used to calculate the cost of climate change are vastly inadequate and need to be updated so that proper decisions can be made about risks associated with global warming.

They said that even the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) has cited the existing economic models and, as a result, has arrived at severely limited assumptions about the costs of global warming.

“It is extremely important to understand the severe limitations of standard economic models, such as those cited in the IPCC report, which have made assumptions that simply do not reflect current knowledge about climate change and its potential impacts on the economy,” Stern, a former chief economist with the World Bank, said in a media release.

It’s a commonly held belief, even within the climate action advocacy community, that significant technological breakthroughs are necessary to harness enough clean, renewable energy to power our global energy demands.

Not so, says a new study published this month, which makes an ambitious case for “sustainable sources” providing 95 percent of global energy demand by mid-century.

This new analysis, “Transition to a fully sustainable global energy system,” published in Energy Strategy Reviews, examines demand scenarios for the major energy use sectors – industry, buildings, and transport – and matches them up to feasible renewable supply sources.

Over on VICE’s Motherboard, Brian Merchant dug into the study and put it into proper context.

It is entirely possible, using technologies largely available today, to power nearly the entire world with clean energy—but we need to conjure the will to make revolutionary strides in public policy and the scale of deployment.

A recent essay says the most pressing current scientific and political challenge is to avoid what is known as “dangerous” global warming – the point where world temperatures become irreversible.

As there’s a 25-to-30-year lag between greenhouse emissions and the full impact of their warming, current climate chaos is a result of carbon spewed in the late 1970s. The hit from more recent discharges – including China’s coal plants – is but pain yet to come.

So we’re dangerously close already.

The board of the American Association for the Advancement of Science, the nation’s leading general science organization, has issued a statement declaring global warming “a growing threat to society.” The first-ever stand by the AAAS, which publishes the journal Science, also attributes recent warming to human activity.