When world leaders first signed the Paris climate agreement back in December, some scientists warned the terms would not sufficiently reduce greenhouse gas emissions to avert catastrophic climate change. Former NASA scientist James Hansen was particularly outspoken, referring to the agreement as a “fraud.” Now 10 other scientists are adding their voices to his, urging world leaders to take a tougher stance.

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Led by Joeri Rogelj, an energy research scholar at the International Institute for Applied Systems Analysis in Switzerland, researchers from around the world published a piece in the journal Nature warning that we are on a perilous path. The other researchers hail from institutions in the Netherlands, the United States, Germany, South Africa, Brazil, China, Austria, and Australia. They concluded while country goals to reduce greenhouse gas emissions could be partially successful, by 2100 Earth could still warm by 2.6 to 3.1 degrees Celsius.

Related: Is the Paris climate accord really a “major leap for mankind”?

An increase of 2.6 to 3.1 degrees Celsius is far more drastic than the Paris climate agreement target, which is designed to keep temperatures from rising to 2 degrees Celsius, and if possible, to limit the increase to 1.5 degrees Celsius. If global temperatures do increase by 3 degrees Celsius, sea levels could rise by 20 feet, which would have a huge negative impact on those living in coastal areas.

Climate change, global warming, 2 degree limit, 2 degrees Celsius, rising sea levels, carbon emissions, greenhouse gas emissions, COP21, melting icebergs, Arctic melting

Many of the goals set by countries target ending dependence on fossil fuels and switching to clean, renewable energies. The researchers said such measures could better lower greenhouse gas emissions than current policies, but the measures probably aren’t enough to save us from surpassing that 2 degree limit.

According to the researchers, nations would essentially have to under promise and over deliver if we’re truly serious about keeping temperatures from rising more than 2 degrees Celsius. They wrote, “…the window for limiting warming to below 1.5 degrees Celsius with high probability and without temporarily exceeding that level already seems to have closed.”

Via Gizmodo

Images via Christopher Michel on Flickr and Development Planning Unit University College London on Flickr