The oft-repeated goal to keep the Earth’s average temperature from rising more than 2 degrees Celsius, a benchmark that was set in the 1970s, is “utterly inadequate to stop global warming, a top U.N. climate scientists said recently.

Petra Tschakert, a professor at Penn State University and lead author of an assessment report for the U.N.’s Intergovernmental Panel on Climate Change (IPCC) said in recent commentary that the 2-degree goal just won’t do enough to stop the ravages of global warming over the next century, according to U.S. News and World Report.

The commentary, which was published in the journal Climate Change Responses, notes that even limiting the rise in temperature to 0.8 degrees Celsius would result in “widespread” negative impacts that would span the globe, and that the warming target should be lowered at least to 1.5 degrees Celsius.

She said the observed impacts on ecosystems, food, and livelihoods rules out the 2-degree goal as an adequate solution.

Getting to the 2-degree mark may be an impossible challenge, considering the fact that it requires heavy scalebacks of carbon dioxide-emitting activities by countries who aren’t too keen about cutting back on industry and hurting their economies for what seems to them some nebulous, far-out goal. Add to that the fact that climate change deniers continue to loudly call for an end to such activities, and the obstacles become almost insurmountable for real change.

However, there have been some positive signs, with a number of gatherings being held between developing and developed nations, including one in Lima, Peru, last December that will lay the groundwork for the big climate summit in Paris this December. Negotiators from 200 countries will come together to try to figure out some sort of international agreement that would scale back carbon emissions.

President Obama, who unveiled the Climate Action Plan in 2013, already faces fierce opposition in the newly Republican-controlled Senate in his attempt to curb U.S. greenhouse gas emissions. He has used his executive authority to add new efficiency measures and new regulations for power plants, as well as tightening the fuel economy standards for automobiles, according to the report.

Obama has also attempted to broker agreements for new solar and nuclear power partnerships with India, and got China to make its first-ever pledge to cut back on carbon emissions.

However, Obama faces an uphill battle with a Republican-controlled Congress filled with global warming deniers. One of the most prominent ones is Sen. Ted Cruz (R-Tex.), who recently announced his bid for the 2016 GOP presidential nomination. Cruz has compared those who believe that global warming is happening to “flat-Earthers” and compared himself to Galileo — although Galileo had nothing to do with disproving flat Earth ideas, which had long since been debunked in his time.