It also signaled the government's intention to respond to mounting concerns over climate change by taking steps to significantly reduce emissions of greenhouse gases (GHGs) believed to cause global warming.

Specifically, the government pledged to reduce the province's annual emissions by one-third between 2006 and 2020.

A separate target was announced for the oil and gas industry: To roll its emissions back to 2000 levels by 2016, at least in part via a requirement for zero flaring at all natural gas wells and production facilities.

The government's focus on climate change was reinforced a few weeks later with the release of its energy plan, which featured a commitment to rely on energy conservation measures and new "green power" sources to meet virtually all of B.C.'s future electricity needs.

That policy-makers have become worried about the risks posed by climate change is understandable. But the throne speech's ambitious GHG targets came as a surprise.

Over the past two decades, the province's emissions have increased at an average annual rate of two per cent. To meet the government's target, emissions will have to fall by 2.5 per cent per year through 2020 - and to do so in the context of a growing population and economy.

Before considering whether this goal can be met, it is instructive to review the trends in and sources of B.C.'s emissions of carbon dioxide (CO2) and other greenhouse gases.

1. Population growth. Our population rose by 31 per cent from 1990 to 2006, leading to increased demands for energy, transportation, residential and commercial space, and many other goods and services -- all of which contribute, directly or indirectly, to higher emissions.
2. The development of a sizable oil and gas industry -- production of fossil fuels is a major source of GHGs. B.C. now ranks as Canada's second-largest natural gas producer (after Alberta), and the province garners one-tenth of its own-source revenue from the industry.

Where do B.C.'s emissions of GHGs come from? On a sectoral basis, the most recent breakdown is as follows:

• Transportation -- 39 per cent
• Energy production (mainly oil and gas) -- 23 per cent
• Other industrial emissions -- 15 per cent
• Residential and commercial -- 11 per cent
• Agriculture, waste and other sources -- 12 per cent

Compared to Canada, the pattern of B.C.'s emissions differs in three ways.

First, transportation accounts for a bigger share of GHG emissions than in other provinces. This presents a challenge, as large-scale reductions in aggregate transportation-related emissions will be difficult to achieve in the short to medium term.

Second, because almost all electricity produced in B.C. is already carbon-free (coming from hydro generation), there is essentially no scope to reduce electricity sector GHG emissions. In contrast, provinces like Alberta, Ontario and Saskatchewan -- which depend heavily on coal-fired power -- can substantially lower emissions by switching to less carbon-intensive energy sources.

Finally, population growth has been a bigger driver of rising emissions in B.C. than in provinces with slow-growing or declining populations.

However, options exist to shift to a less carbon-intensive economy over time.

Some examples: Replacing diesel trucks and buses with new fleets running on liquefied natural gas; capturing methane gas from landfills; encouraging building retrofits; and using pine-infested wood and other wood waste to provide a new source of power -- although, as noted above, this would do little to reduce the already low level of GHG emissions from our electricity sector.

There are also opportunities to accelerate the commercialization of alternative energy technologies being developed by innovative B.C. companies. Tougher tailpipe emission standards for new vehicles would help to dampen transportation-related emissions. And designing a system for registering and trading carbon offsets and credits with neighbouring jurisdictions should be part of a sensible market-based regime for managing CO2 emissions.

At the same time, B.C. cannot ignore the economic consequences of greenhouse gas mitigation and must be realistic about what can be accomplished through unilateral action. By itself, B.C. accounts for a little more than one-tenth of one per cent of global GHG emissions.

As the government fleshes out its climate change plans, it will need to keep an eye on B.C.'s competitive position as a leading North American trade and tourism gateway.

Within Canada, B.C. should recognize that it is better to set emission and efficiency standards for vehicles, fuels, and appliances on a national rather than a provincial basis. In a world still dependent on fossil fuels, B.C. has nothing to gain and much to lose if the oil and gas industry concludes it is no longer welcome here.