Climate activists blocked traffic in Washington D.C., early Monday in an effort to shut down the city as part of the Global Climate Strike. The protests come ahead of the United Nation's landmark summit on the crisis. More than 60 world leaders attended the Climate Action Summit, which opened with ominous words from U.N. Secretary General António Guterres.

"Nature is angry," Guterres said. "And we fool ourselves if we think we can fool nature because nature always strikes back and around the world nature is striking back with fury." Former U.N. climate negotiator Christiana Figueres believes that anger, especially in humans' responses to climate change, is what ultimately could change things for the better.

"We are definitely moving in the right direction," Figueres said in an interview with CBSN on Monday. "The global economy is becoming decarbonized but way too slowly. And that is why I'm actually quite grateful. For the anger and the outrage that is out there in the streets because I think that is going to jolt everyone."

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Figueres was encouraged by the tone of the U.N. summit Monday and was particularly impressed by Greta Thunberg's impassioned speech.

"Greta in her usual style delivered a scathing speech about the irresponsibility with which we have been non-acting and was very, very clear about if we don't do our job she and her generation will not forgive us," Figueres said. "So just swallow that one for a moment."

Christiana Figueres seen September 19, 2019. AP

Figueres stressed that the world is running out of time to act and that speed is of the utmost importance. Similar concerns were on her mind when she first led negotiations for the original Paris Accord in 2015 — an agreement she believes the U.S. will still leave in 2020, whether Donald Trump is in office or not.

"The important thing here I think to remember is that the dovetailing of the United States back into international efforts is actually already being prepared by 70% of the economy of the U.S. that continues to decarbonize independently of what they're hearing from the White House because they understand that it is in their interest," Figueres explained. "So the preparation for reentry is already there."

Figueres takes a multi-faceted approach to reducing carbon emissions and believes that the onus falls not just on countries, governments and corporations — but on the individual, as well.

The diplomat helped found Global Optimism, a company that advocates for social and environmental change through initiatives that reduce carbon emissions like Mission 2020. Recently, Global Optimism partnered with Amazon to co-found the Climate Pledge, which "calls on signatories to be net zero carbon across their businesses by 2040 — a decade ahead of the Paris Agreement's goal of 2050," according to a press release.

"We are all co-responsible," Figueres said.