Baroness Sandip Verma (pictured) said that the rate of global warming might have decreased, and that this could support the effectiveness of green policies

Government environmental measures may already have helped to slow down global warming, an energy minister has claimed.

Baroness Sandip Verma said the rate of warming might have decreased, which could support the effectiveness of green policies.

Her comments came as Viscount Ridley, a Conservative peer and critic of government efforts to stop temperature rises, questioned her on when warming would start again.

He told peers at question time in the House of Lords: 'The fifth assessment report of the Intergovernmental Panel On Climate Change has confirmed in the same words that there has been a hiatus in global warming for at least the last 15 years.'

And he asked Lady Verma: 'Would you give us the opinion of your scientific advisers as to when this hiatus is likely to end?'

Lady Verma told him: 'You raise a couple of issues that we would dispute in a longer debate, but what we do recognise is that there a change in weather patterns happening across the globe, that climate change is occurring.

'It may have slowed down, but that is a good thing. It could well be that some of the measures we are taking today is helping that to occur.'

For Labour, Baroness Bryony Worthington said the fifth report would be published on Friday.

In April, the IPCC said it is '95 per cent' certain that climate change is man made, but still could not explain why the world has barely got any hotter in the last 15 years.

The IPCC report said that sea levels have risen by seven inches (19cm) since 1901 and are expected to rise a further 10 to 32 inches (26 to 82cm) by the end of the century.

It added that concentrations of CO2 and other greenhouse gases in the atmosphere have increased to levels that are unprecedented in at least 800,000 years.

But the landmark report conceded that world temperatures have barely risen in the past 15 years, despite growing amounts of greenhouse gases being pumped into the atmosphere.

In April, the IPCC said it is '95 per cent' certain that climate change is man made, but still could not explain why the world has barely got any hotter in the last 15 years. During today's House of Lords session, Baroness Bryony Worthington said the fifth assessment report on this research would be published on Friday

Independent research similarly found that there has been little increase in the average temperature of the Earth’s surface since the turn of the century. Previous studies claimed this hiatus has lasted for 15 years, but Professor Ross McKitrick from University of Guelph believes temperatures have remained constant since 1995

'[The fifth report] is likely to say yet again that there is incontrovertible proof now that climate change is a serious issue and we all must take notice of that,' Baroness Worthington added.

She asked Lady Verma: 'Would you accept that Friday might be a good opportunity to point that out to some of the backbenchers in your party.'

Lady Verma replied: 'It isn't just about backbenchers on my side. I think it is about making sure we deliver an informed debate and perhaps, thus far, that debate hasn't really taken place.'

Independent research recently discovered that, since the turn of the century, there has been little increase in the average temperature of the Earth’s surface.

WHAT IS THE IPCC AND WHY DOES THE REPORT MATTER? WHAT IS THE IPCC? A scientific body with 195 member countries. The panel was established by the UN in 1988 to assess the causes and impacts of climate change. Since then, it has released four assessments, each stating the human link to global warming with more certainty than the previous one. The IPCC doesn't conduct its own research, but appoints hundreds of experts to review and summarise the latest scientific studies on climate change. It is headed by Rajendra Pachauri, a scientist from India. WHAT IS THE REPORT FOR? The report forms the scientific basis for U.N. negotiations aimed at curbing global warming. It will be a reference point for governments as they negotiate a new global climate agreement, which is supposed to be adopted by 2015 and to take effect in 2020. WHY HAS THE IPCC COME UNDER CRITICISM? It has been argued that the IPCC process is so time-consuming and laborious that by the time the assessments are published they are already out of date. A series of errors embarrassed the authors of the 2007 assessment, including the incorrect statement that the glaciers in the Himalayas would disappear by 2035. There has also been criticism about the IPCC's lack of openness. Advertisement

Previous studies claimed this hiatus has lasted for 15 years, but new research believes the temperature has remained almost constant since 1995.

The conclusions were made by an economics professor Ross McKitrick from the University of Guelph in Canada who studied average land and ocean temperatures from the Hadcrut4 temperature series, dating back to 1850.

Hadcrut4 is a monthly record of temperature readings created by the Hadley Centre of the UK Met Office, and the University of East Anglia’s Climatic Research Unit.

It combines sea surface temperatures with land surface air temperatures into a grid that shows variations and anomalies.

Professor McKitrick also compared these readings to those taken by the Remote Sensing Systems (RSS) satellite, which has measured upper air temperatures since 1979.