A key climate treaty finalized in Paris last year will enter into force on Nov. 4, 30 days after the conditions necessary for its implementation were finally met. The accord, negotiated by nearly 200 countries and currently ratified by 73 of them, as well as the European Union, aims to prevent a catastrophic rise in global temperatures.

The agreement needed to be ratified by at least 55 parties accounting for at least 55 percent of global emissions for it to come into effect 30 days after the two conditions were met. On Tuesday, the EU Parliament ratified the accord, pushing it past that threshold.

“This is a momentous occasion,” United Nations Secretary-General Ban Ki-moon said in a statement released Wednesday, after the latest instruments of ratification were deposited. “What once seemed unthinkable, is now unstoppable. Strong international support for the Paris Agreement entering into force is a testament to the urgency for action, and reflects the consensus of governments that robust global cooperation, grounded in national action, is essential to meet the climate challenge.”

The long-term goal of the climate agreement, drafted during the United Nations Climate Change Conference in Paris in December 2015, is to keep the rise in average global temperatures “well below” 2 degrees Celsius (3.6 degrees Fahrenheit) above the pre-industrial levels, and pursue efforts to keep it within 1.5 degrees Celsius (2.7 degrees Fahrenheit). However, given that global temperatures have already risen by almost 1 degree Celsius (1.8 degrees Fahrenheit), many experts now believe that the target is unlikely to be met.

“Now we must move from words to deeds and put Paris into action. We need all hands on deck — every part of society must be mobilized to reduce emissions and help communities adapt to inevitable climate impacts,” Ban said.

In order to meet the aspirational goal, developed nations have pledged an absolute reduction in their emissions, while developing countries such as China have set deadlines to peak greenhouse gas emissions. The U.S., for instance, has pledged to slash its emissions by up to 28 percent of its 2005 levels by 2025, while China has promised to peak carbon dioxide emissions by 2030.

“This agreement will help delay or avoid some of the worst consequences of climate change. ... This gives us the best possible shot to save the one planet we’ve got,” U.S. President Barack Obama said in a speech lauding the agreement. “If we follow through on the commitments that this agreement embodies, history may well judge it as a turning point for our planet.”

However, many climate scientists have expressed fears that the agreement, and the pledges made under it, are too little, too late. They have slammed what they term is “false optimism” previously espoused by world leaders, insofar as reining in the rise in global temperatures is concerned.

Another argument in favor of tempering expectations came in the form a study published Wednesday in the journal Nature. In it, researchers who created the world’s largest database of global methane emissions found we may have grossly underestimated emissions of a potent greenhouse gas by the global fossil fuel industry.

According to the study, emissions of methane — a greenhouse gas that is short-lived but has a more powerful warming effect than carbon dioxide — produced during the production of oil, coal and natural gas are 20 to 60 percent higher than thought. And, accounting for natural sources of the gas — wild animals, geological sources, etc. — these emissions may be 60 to 100 percent greater than previously estimated.

“Emissions scenarios currently used for climate prediction need to be reassessed taking into account revised values for anthropogenic methane emissions,’ Grant Allen, a professor at the University of Manchester, wrote in a commentary in Nature.

The silver lining, if there is one, is that since methane is short-lived, efforts to curb its emissions from the gas and oil industry now are likely to bear fruit in the span of just a few years.

“Reducing methane emissions now will reduce climate forcing in only a few years — it takes much longer for CO2. And since fossil fuel methane emissions are higher than previously thought, the potential to reduce climate forcing from this specific source is also greater,” Lead author Stefan Schwietzke from the University of Colorado, told the Guardian.