India urged rich nations against applying a carbon tariff on steel and other imports, on the sidelines of UN climate talks in Bonn on Tuesday.

Both U.S. and European Union policymakers have considered penalising imports of products such as steel and cement, whose manufacture generates a lot of carbon emissions, from countries with softer climate policies.

It will be hard work getting rich nations to agree cuts in greenhouse gases that are deep enough to satisfy the demands of developing countries at climate talks, UN's climate chief told Reuters on Monday.

Some 175 nations are meeting this week in Bonn in one of a series of UN-led meetings meant to forge a deal in Copenhagen in December to replace or extend the Kyoto Protocol.

World leaders at the G20 summit disappointed environmental groups on Thursday who said their commitment to fight climate change had been vague.

The leaders reaffirmed a previous commitment to sign a U.N. climate deal this year, a step the U.N. climate-change chief said was useful, though action would be better.

A draft statement which would confirm G20 leaders' commitment to sign a new climate pact in December and support low-carbon growth drew mixed reactions from green groups and policymakers Tuesday.

Environment analysts say more was unlikely from an April 2 summit of leaders of developed and emerging countries focused on preventing global recession from becoming a depression.

A G20 summit next week will test leading countries' appetite to fight climate change after spending trillions bailing out banks and shoring up the global economy.

The April 2 meeting in London of leaders of major developed and emerging economies aims to battle a financial crisis.

Global investment in clean energy and climate-friendly technologies leapt in the last three months but full-year levels won't recover until 2010 or 2011, analysts said on Wednesday.

Falling energy demand and more expensive debt have hurt large renewable projects for example in wind and solar power. Recession has cut risk appetite, curbing funding for clean technology start-ups.