The United Nations' annual talks on climate change have opened in Doha, Qatar.
Delegates from nearly 200 countries are meeting to try to extend an existing pact to curb the emissions that cause global warming and begin drafting a new one to replace it.
This year's conference will be held with a particular sense of urgency. The Kyoto Protocol, the only international, binding treaty on the gases that contribute to climate change, is set to expire at the end of the year.
South African Foreign Minister Maite Nkoana-Mashabane, outgoing president of the UN Climate Change Conference, opened the November 26 meeting with a warning.
"Urgent action is needed if we are to avoid a global catastrophe in the next generation. We cannot waver in our resolve to rise to this challenge," Nkoana-Mashabane said.
Several reports released in the week before the talks warning of dire consequences if current climate policies continue have also raised the stakes.
The Kyoto agreement, considered a breakthrough when it was signed in 1997, mandates reductions in emissions for industrialized nations of carbon dioxide and other gases in the atmosphere that trap heat, leading to increased temperatures on Earth.
The United States never ratified the treaty over fears of negative economic effects and due to the plan’s lack of emissions commitments for China. That meant the world's top two emitters were not bound by the protocol.
Canada, Japan, and Russia have also since dropped out of the treaty.
Despite its weaknesses, delegates in Doha will look to extend the protocol for several more years, ensuring that an agreement remains in place until a new and improved pact takes effect.
At last year's climate talks in Durban, South Africa, countries agreed to formulate a replacement for Kyoto by 2015 that would take effect in 2020.
Edward Cameron, the director of the International Climate Initiative at the World Resources Institute in Washington, says this year's conference will lay the framework for negotiations on the new treaty.
He says it could begin to tackle what has inhibited progress in the past -- the issue of equality in countries' commitments.
"We're not currently where we need to be, and in that context, Kyoto should be seen as a vital first step. Now the challenge is how do we build on that?" Cameron says.
"How do we bring more countries into the system so that they're progressively reducing emissions as well? How do we ensure that there is a balance between what Europe and other industrialized countries are doing with what the United States can do and what some of the major emerging economies can do?"
Negotiators will also attempt to boost lagging funding for climate change mitigation projects and take up the social and economic factors behind deforestation and forest degradation, which are responsible for up to one-fifth of global carbon emissions.
The need to take bolder action against climate change and toward a low-carbon global economy was underscored by several reports released ahead of the talks.
The UN’s World Meteorological Organization (WMO) on November 20 said greenhouse gases in the atmosphere reached a record high in 2011 and raised concern about the capacity of the ocean to continue to absorb large amounts of carbon dioxide.
The WMO's Christian Blondin says the climate appears to be warming at an alarming rate.
"What we can deduce from what we've observed is that we are following the scenarios which are the least optimistic. We are on scenarios which correspond to the higher emissions than were forecast, due to increased demography and so forth," Blondin said.
"And so the likelihood that we could stay under a 2 degree [Celsius] [warming] threshold is more and more challenging as time runs."
A November 18 World Bank report said current climate policies could mean up to a 4 degree Celsius increase in average global temperature by 2100.
Such warming could unleash more storms like Hurricane Sandy, which wreaked havoc on the Caribbean and eastern coast of the United States last month, along with severe heat waves, droughts, crop failures, and rising sea levels. Many of the world's poorest people would be hit hardest.