Image caption South African President Jacob Zuma: Climate change is "a matter of life and death"

Canada will not make further cuts in its greenhouse gas emissions under the Kyoto Protocol, and may begin formally withdrawing next month.

Though not a surprise, the news will anger poor countries that say the rich are reneging on pledges made 14 years ago when the protocol was signed.

They see the protocol as the only way to make emission cuts legally binding.

Also on the first day of the UN climate summit in South Africa, the UK was criticised over support for tar sands.

In the main conference hall, delegates heard South African President Jacob Zuma call for meaningful progress.

"For most people in the developing world and Africa, climate change is a matter of life and death," he said.

"In these talks, states, parties will need to look beyond their national interests to find a global solution for the common good and benefit of all humanity."

Different worlds

The consequence for some of the islands will be extinction Selwyn Hart, Aosis

The very differing interpretations of "national interests" did not take long to surface.

Canada declared four years ago that it did not intend to meet its existing Kyoto Protocol commitment - to bring annual emissions in the period 2008-12 down by 6% from their 1990 level.

They have in fact risen by about one-third since 1990.

And just a few hours after talks began in the Durban conference hall, Canadian environment minister Peter Kent was confirming to reporters in the capital Ottawa that its involvement with Kyoto was over.

"We will not make a second commitment to Kyoto," he said. "We don't need a binding convention."

Image caption Tar sands exploitation comes at a heavy environmental cost, locally as well as globally

Since the election of Stephen Harper's Conservative government in 2006, Canada has sought to align its stance with its most important trading partner, the US.

It fears that its economy would suffer if it took on stronger curbs than its southern neighbour.

Canadian network CTV reported that the government would begin formally withdrawing from the protocol next month.

Mr Kent declined to comment.

But with 12 months notice needed to withdraw, and the current set of targets expiring at the end of next year, the timescale for a formal secession would make sense and would then put Canada in the same bracket formally as the US, which withdrew under President George W Bush.

Russia and Japan have also said they will not make further emission cuts under the protocol, though it is not known whether they plan formally to withdraw.

In Durban, the US deputy climate negotiator Jonathan Pershing said he did not see existing pledges on curbing emissions by 2020 changing.

DURBAN CLIMATE CONFERENCE Summit will attempt to agree the roadmap for a future global deal on reducing carbon emissions

Developing countries are insisting rich nations pledge further emission cuts under the Kyoto Protocol

Delegates also aim to finalise some deals struck at last year's summit

These include speeding up the roll-out of clean technology to developing nations…

… and a system for managing the Green Climate Fund, scheduled to gather and distribute billions of dollars per year to developing countries

Progress may also be made on funding forest protection

"The idea that countries would change their current pledges that they listed in the Cancun agreements [from last year's summit in Mexico] seems unlikely to me," he told reporters.

"I don't see the major economies shifting those actions."

At a meeting of the Major Economies Forum (MEF) earlier this month - the body that brings together 17 of the world's biggest greenhouse gas emitters - India and Brazil joined the US in wanting to delay beginning talks on a new global climate agreement until at least 2015.

The EU and many smaller developing states want to reach agreement in Durban on starting talks pretty much immediately, reaching agreement by 2015 and cutting emissions by 2020.

Reports by numerous organisations, most recently the International Energy Agency, have concluded that in order to meet the goal of keeping global average temperature rise since pre-industrial times below 2C, emissions should peak and begin to fall around 2020, if not earlier.

The current pledges to which Mr Pershing referred will not achieve this.

Fossil fired

Speaking for the Alliance of Small Island States (Aosis), Barbadian delegate Selwyn Hart said his group was not prepared to contemplate delay.

Climate change glossary Select a term to learn more: Adaptation Adaptation Action that helps cope with the effects of climate change - for example construction of barriers to protect against rising sea levels, or conversion to crops capable of surviving high temperatures and drought.

"At the heart of any agreement should be the principle that no country is expendable," he said.

"It's morally and ethically indefensible to sign an agreement that will result in the demise of a single nation state. The consequence for some of the islands will be extinction."

The UK, meanwhile, received one of the unwanted "Fossil of the Day" awards from a coalition of campaign groups.

They were angered by reports, deriving from a Freedom of Information (FoI) request by the Co-operative, that the UK has been lobbying to weaken EU rules on oil from Canadian tar sands.

Extracting oil from the tar deposits that spread across Canada's prairie provinces is much more energy-intensive than conventional oil drilling, and also uses huge amounts of water.

Some climate scientists say exploiting the reserves is simply incompatible with curbing global warming.

Follow Richard on Twitter