Zichal was referring to a deal Obama struck with Chinese President Xi Jinping over the weekend to limit emissions, consumption and production of hydrofluorocarbons (HFCs).
The short-lived, but potent, greenhouse gas is used in refrigerators and air conditioners. The White House said ramping down on global HFC emissions could reduce the equivalent of 90 gigatons of carbon dioxide by 2050.
The HFC agreement is the start of a “long and robust international agenda on climate change” for Obama’s second term, Zichal said.
Zichal noted that Secretary of State John Kerry also has talks scheduled with India about reducing greenhouse gas emissions.
“The time to act is now,” Zichal said.
Getting emerging economies, such as China and India, to slash emissions has proven a hitch in global climate negotiations for the past two decades. Those nations have argued making commitments would handcuff their economies, leaving millions in poverty.
In turn, industrialized nations have been skittish about signing climate accords. They argue doing so would handicap domestic firms that compete against companies exempted from climate treaties.
But the economies of China and India have boomed since the last global climate treaty was signed in 1997, bringing millions out of poverty.
At the same time, global emissions continued rising while those economies churned at full speed, jeopardizing goals of keeping temperatures from rising 2 C (3.6 F) by 2020.
Those factors figure to bring renewed international pressure on China, India and other emerging economies to rein in emissions.