Image caption Injection of sulphate aerosols is designed to mimic the cooling effect of volcanic eruptions

There is strong support among the public in the US, UK and Canada for more research on geo-engineering technology, a study has suggested.

The survey focused on "solar radiation management", which involves reflecting energy from the Sun away from the Earth's surface, and received support from 72% of respondents.

The internet survey was commissioned by researchers from North America.

The findings appear in the Environmental Research Letters journal.

Writing in their paper, the researchers said the main focus on tackling climate change has been mitigation and adaptation, but the concept of geo-engineering had been gaining attention.

"Deliberate large-scale engineering to reduce or offset climate change driven by greenhouse gases... comprises an array of techniques that can broadly be divided into two very different approaches: carbon dioxide removal and solar radiation management (SRM)," they said.

"Most SRM techniques act by increasing the albedo of the atmosphere through methods such as the injection of sulphate aerosols into the stratosphere where they would reflect some solar energy back to space, lowering the global temperature."

They added that although the technology had been discussed and researched since the 1960s, there had been no data on public awareness or public opinions on the use of such measures.

The team commissioned internet-based research firm Knowledge Networks to carry out an 18-question survey between November and December 2010 to gauge awareness and attitudes towards the concept of geo-engineering.

Out of 3,105 respondents, two-thirds of which were from the US, they found that 72% approved of more research into climate-manipulating technology.

However, the survey showed that three-quarters of the people questioned thought that the Earth's climate system was too complicated to be "fixed" with just one technology.

The majority of respondents, the researchers added, were also inclined to say that the use of SRM technologies was an "easy way out" of continuing to burn fossil fuels and did not offer a long-term solution.

'Spicing things up'

A pioneering test, by the UK-based Stratospheric Particle Injection for Climate Engineering (Spice) project, was originally set to begin an experiment in October but was delayed for six months in order to address concerns voiced by critics.

The Spice team plan to use a balloon and a kilometre-long hose to spray water into the upper atmosphere - a prelude to spraying climate-cooling sulphate particles.

Image caption The postponed Spice test plans to pump water droplets 1km above the ground

Researchers involved in the project calculates that 10 or 20 giant balloons at a 20km altitude could release enough particles into the atmosphere to reduce the global temperature by around 2C (3.6F).

But opponents, such as the EcoNexus NGO, argue that even testing could have harmful impacts, and that questions of ethics and international law need to be answered.

On its website, EcoNexus lists a number of other concerns, including the lack of certainty over the possible impacts of geo-engineering on biodiversity.

In December 2010, the 193 parties of the international Convention on Biological Diversity (CBD) agreed to impose a moratorium on the use of the technique until there was an "adequate scientific basis on which to justify such activities and appropriate consideration of the associated risks".

The ruling, which is not legally binding, is expected to be in force from 2012, although it is not expected to affect research projects in the short-term.