Higher-than-expected immigration would raise emissions, but this isn't factored into forecasts, expert says

* German emissions f'casts underestimate immigration-expert

* Up to one million refugees expected to arrive this year

* Unclear how much CO2 refugees produce, how many will stay

By Caroline Copley

BERLIN, Dec 4 (Reuters) - An influx of up to one million refugees to Germany this year may make it harder for the government to achieve its CO2 reduction targets in 2020, an adviser to the government on energy policy has warned.

Germany sees itself as a green leader in the fight against climate change and has set itself an ambitious goal to reduce CO2 emissions by 40 percent by 2020 compared to 1990 levels.

But experts say this goal is already at serious risk, partly due to its reliance on coal-fired power plants and slow progress on implementing a climate action plan agreed last year.

Further complicating this picture is higher-than-expected immigration, said Andreas Loeschel, professor of energy and resource economics at the University of Muenster.

Population forecasts are one of the components used to determine estimates for future emissions.

"The German government's official projections are built on assumptions for population growth which are outdated," said Loeschel, who also heads an independent committee monitoring the progress of Germany's shift away from fossil fuels and nuclear power known as the 'Energiewende.'

Up to one million refugees are expected to arrive in Germany this year. But the government's current climate projections are based on net annual immigration of around 200,000 people.

Updated population forecasts from the Federal Statistics Office in April assume net annual immigration exceeding 200,000 until at least 2018, and for 500,000 this year.

But Loeschel says these forecasts could also be deemed too conservative since they were published before the sharp increase in refugees this summer. Taking this into account, Germany's population in 2020 could be 2-2.5 million higher than projected.

According to the Environment Ministry, a one million increase in the population raises CO2 emissions by 6.4 million tonnes of CO2 per year.

This is equivalent to around half the CO2 the government plans to save by mothballing 2.7 gigawatts of power generation from brown coal, a decision that was agreed this summer after months of wrangling with trade unions.

A Economy Ministry spokeswoman said it did not have any figures on how the refugee influx might impact energy consumption and CO2 emissions, but added there were a variety of measures to increase energy efficiency and lower consumption.

Loeschel stresses his analysis is based on rough calculations and doesn't consider refugees' living standards.

Those on lower incomes are likely to consume and travel less, for example. But they also tend to live in poorly insulated buildings, a major culprit for emissions.

It is also unclear how many will stay long-term.

Because of this, Claudia Kemfert, energy economist at the DIW in Berlin, says the biggest risk to Germany's climate goals remains the high share of coal in the energy mix.

"It is unknown how many citizens Germany will have in 2020, where and how they live," she said. "The average person in Germany produces 10 tons of CO2 per year. If the living standard is much lower, the CO2 footprint will be much lower." (Editing by Tom Heneghan)

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