Air pollution blankets a mountain range in Tehran, Iran, Dec 23, 2020. Iran's capital and its major cities have been plunged into darkness as rolling outages in recent weeks left millions with no electricity for hours. With toxic smog blanketing the skies in Tehran and the country buckling under the strain of the pandemic and sanctions targeting Iran’s oil and gas industry, speculation about the spate of blackouts gripped social media. Soon, fingers pointed at an unlikely culprit: Bitcoin. (AP Photo/Ebrahim Noroozi)

Air pollution blankets the skyline in Tehran, Iran, Wednesday, Dec 23, 2020. Iran's capital and its major cities have been plunged into darkness as rolling outages in recent weeks left millions with no electricity for hours. With toxic smog blanketing the skies in Tehran and the country buckling under the strain of the pandemic and sanctions targeting Iran’s oil and gas industry, speculation about the spate of blackouts gripped social media. Soon, fingers pointed at an unlikely culprit: Bitcoin. (AP Photo/Ebrahim Noroozi)

In this Friday, April 24, 2020 file photo, activists place thousands of protest placards in front of the Reichstag building, home of the german federal parliament, Bundestag, during a protest rally of the 'Fridays for Future' movement in Berlin, Germany. World leaders breathed an audible sigh of relief that the United States under President Joe Biden is rejoining the global effort to curb climate change, a cause that his predecessor had shunned. (AP Photo/Michael Sohn, File)

FILE - In this Feb. 4, 2020 file photo, Britain's Prime Minister Boris Johnson launches the upcoming UK-hosted COP26 UN Climate Summit in London, England. World leaders breathed an audible sigh of relief that the United States under President Joe Biden is rejoining the global effort to curb climate change, a cause that his predecessor had shunned. (Jeremy Selwyn/Pool via AP, File)

FILE - In this Sept. 19, 2019 file photo, an aircraft passes the rising sun during take off at the international airport in Frankfurt, Germany. World leaders breathed an audible sigh of relief that the United States under President Joe Biden is rejoining the global effort to curb climate change, a cause that his predecessor had shunned. (AP Photo/Michael Probst, File)

FILE - In this Friday, Nov. 30, 2018 file photo smoke rises from a factory as a truck loaded with cars crosses a bridge in Paris, France. World leaders breathed an audible sigh of relief that the United States under President Joe Biden is rejoining the global effort to curb climate change, a cause that his predecessor had shunned. (AP Photo/Michel Euler, File)

FILE - In this Jan. 11, 2021 file photo, French President Emmanuel Macron stands during the One Planet Summit, at The Elysee Palace, in Paris, France. World leaders breathed an audible sigh of relief that the United States under President Joe Biden is rejoining the global effort to curb climate change, a cause that his predecessor had shunned. (Ludovic Marin, Pool Photo via AP, File)

FILE - In this Dec. 8, 2019 file photo, a hundred activists hold portraits of President Emmanuel Macron to urge France to take action during the U.N. COP 25 climate talks in Madrid, during a gathering at Place du Trocadero facing the Eiffel Tower in Paris, France. World leaders breathed an audible sigh of relief that the United States under President Joe Biden is rejoining the global effort to curb climate change, a cause that his predecessor had shunned. (AP Photo/Francois Mori, File)