Canada's greenhouse-gas emissions rose 25 per cent between 1990 and 2005, the biggest percentage increase among G8 countries over the same time period, according to new Statistics Canada figures released Tuesday.

The Statistics Canada study Human Activity and the Environment found that Canada's greenhouse gas emissions rose from 596 megatonnes to 747 megatonnes of carbon-dioxide equivalent emissions, the standard of measurement for greenhouse gases.

The study said the resulting growth in greenhouse gases is in part attributable to a number of other changes in the country over the same time period, notably demographic and economic growth.

Canada's population grew by 16.4 per cent over the same time period, while its gross domestic product grew 58.6 per cent from 1991 to 2006.

The study, published to coincide with Earth Day, said Canada has about 0.5 per cent of the world's population but contributes about two per cent of the total greenhouse gas emissions.

Almost three-quarters of Canada's greenhouse-gas emissions were from the combustion of fossil fuels, with about one-third of those emissions coming from transportation.

Canadians are also among the highest per capita polluters in the world, producing an average of 23 tonnes of carbon dioxide equivalent emissions per person each year, according to the study.

Citing figures from the UN Framework Convention on Climate change, the study said Canada's per capita greenhouse gas emissions was the third-highest in the world, trailing only Australia (27.7 tonnes per person) and the United States (24.4 tonnes).

Driving a mid-sized car about 5,000 km produces about one tonne of carbon-dioxide equivalent emissions.

While the overall numbers paint a less-than-rosy picture, the study said Canada's greenhouse gas emissions stabilized from 2003 to 2005, a change they attribute to reduced coal and increased hydro and nuclear generation for electricity production, as well as reduced demand for heating fuels because of warmer winters.

Canada's greenhouse gas intensity — the amount of greenhouse gases emitted per unit of economic activity — was six per cent lower in 2005 than 2003.

Those 2005 emission levels were still 33 per cent above Canada's Kyoto target, the study said.

The agency also notes that climate change resulting from increased greenhouse gas emissions will have a profound effect on Canada's natural resources and ecosystems. It said warm weather has already contributed to the reduction of Arctic sea ice and has produced more favourable conditions for the mountain pine beetle in British Columbia and Alberta.