* China to be top cumulative emitter since 1990
* Strong economic growth skews historic responsibility
* Paris U.N. deal to set goals for emissions beyond 2020
By Alister Doyle, Environment Correspondent
OSLO, April 13 China is poised to overtake the
United States as the main cause of man-made global warming since
1990, the benchmark year for U.N.-led action, in a historic
shift that may raise pressure on Beijing to act.
China's cumulative greenhouse gas emissions since 1990, when
governments were becoming aware of climate change, will outstrip
those of the United States in 2015 or 2016, according to
separate estimates by experts in Norway and the United States.
The shift, reflecting China's stellar economic growth,
raises questions about historical blame for rising temperatures
and more floods, desertification, heatwaves and sea level rise.
Almost 200 nations will meet in Paris in December to work
out a global deal to fight climate actions beyond 2020.
"A few years ago China's per capita emissions were low, its
historical responsibility was low. That's changing fast," said
Glen Peters of the Center for International Climate and
Environmental Research, Oslo (CICERO), who says China will
overtake the United States this year.
Using slightly different data, the U.S.-based World
Resources Institute think-tank estimated that China's cumulative
carbon dioxide emissions will total 151 billion tonnes for
1990-2016, overtaking the U.S. total of 147 billion next year.
The rise of cumulative emissions "obviously does open China
up to claims of responsibility from other developing countries,"
said Daniel Farber, a professor of law at the University of
In a U.N. principle laid down in 1992, rich nations are
meant to lead in cutting greenhouse gas emissions because their
wealth is based on burning coal, oil and natural gas since the
Industrial Revolution began in the 18th century.
Emerging nations, meanwhile, can burn more fossil fuels to
catch up and end poverty. But the rapid economic rise of China,
India, Brazil and many other emerging nations is straining the
traditional divide between rich and poor.
"All countries now have responsibility. It's not just a
story about China -- it's a story about the whole world," said
Ottmar Edenhofer of the Potsdam Institute for Climate Impact
Research and co-chair of a U.N. climate report last year.
India will overtake Russia's cumulative emissions since 1990
in the 2020s to rank fourth behind China, the United States and
the European Union, according to the CICERO calculations.
China surpassed the United States as the top annual emitter
of carbon dioxide in around 2006 and now emits more each year
than the United States and the European Union combined. Per
capita emissions by its 1.3 billion people are around EU levels.
Beijing says the best yardstick for historical
responsibility is per capita emissions since the 18th century,
by which measure its emissions are less than a tenth those of
the United States.
But stretching liability so far back is complicated.
Should heat-trapping methane gas emitted by rice paddies in
Asia in the 19th century, now omitted, count alongside
industrial carbon emissions by Europe? Should Britain be
responsible for India's emissions before independence in 1947?
Lawyers say it is difficult to blame people living today for
emissions by ancestors who had no inkling that greenhouse gases
might damage the climate.
"I feel very uneasy about going back more than a generation
in terms of historic responsibility," said Farber, arguing that
Berlin could hardly be blamed if someone died by setting off a
rusting German World War One landmine in France.
All governments are now working out plans for a climate
summit in Paris in December that will set targets for 2025 or
2030. Beijing set a goal last year of peaking its rising
emissions around 2030, perhaps before.
"China is acting. It has acknowledged its position as a key
polluter," said Saleemel Huq, of the International Institute for
Environment and Development in London.
And historical responsibility is at the heart of talks on
solving the problem.
The U.N. panel of climate scientists estimated last year
that humankind had emitted 1.9 trillion tonnes of carbon dioxide
since the late 19th century and can only emit a trillion more
before rising temperatures breach a U.N. ceiling of 2 degrees
Celsius (3.6 Fahrenheit) above pre-industrial times.
Any fair formula for sharing out that trillion tonnes, or
roughly 30 years of emissions at current rates, inevitably has
to consider what each country has done in the past, said Myles
Allen, a scientist at Oxford University.
"Until people start thinking about blame and responsibility
they are not taking the problem seriously," he said.
(Editing by Catherine Evans)