The home furnisher's announcement came as officials from nearly 200 countries met in Bonn, Germany, to prepare for a UN climate summit in Paris in December.

One of the biggest contentions lodged against richer countries at that meeting has been that they are unwilling to pay more money to poorer states to help them overcome challenges posed by global warming.

IKEA's pledge was another example of private companies going above and beyond what some governments are doing to promote renewable energy. Earlier this week, Europe's six largest energy companies implored UN leaders to allow them a bigger role in shaping the global bloc's policies on climate change.

Wind and solar

The family-owned group said it would invest 500 million euros on wind power and around 100 million euros on solar energy over the next five years. Its charitable arm, the IKEA Foundation, said it would put 400 million euros toward supporting some of the worst-hit families and communities that are suffering from floods, droughts and desertification.

But what made IKEA's billion-euro commitment so noteworthy was its proportion to the company's size. Last year, the retailer reported revenues totaling 28.7 billion euros. Since 2009, IKEA has invested 1.5 billion euros in green energy production, part of its goal to one day use only energy that it produces.

The company has already installed some 700,000 solar panels on the roofs of its well-known, boxy blue-and-yellow stores. It also owns hundreds of wind turbines in the US and Canada.