The Kyoto treaty, even from an environmentalists’ point of view, is flawed and insufficient to stop global warming. It was always the intention of environmentalists that it was to be a stepping stone to something more. But practical experience is showing that environmentalists were wrong to expect that nations would be willing to sacrifice their own prosperity in exchange for something so intangible. The accepted flaws that I am aware of include the following;
1) Kyoto was always voluntary
While there is a punishment mechanism, compliance was always voluntary since there was no way to enforce the punishment mechanism. Moreover, the punishment mechanism doesn’t actually reduce greenhouse gases, it just means that wealthy nations can pay to have their sins absolved like some kind of middle age indulgence. The USA, which promised big greenhouse gas emission cuts, never even ratified the treaty.
2) Kyoto didn’t include all nations
Kyoto targeted the ‘wealthy’ first world nations but ignored any other nation entirely, not even providing them with proposed limits for their greenhouse gas emission increases. Today, with China’s greenhouse gas emissions exceeding those of the USA and increasing rapidly, I think we can safely say that was a mistake.
3) Kyoto targets were arbitrarily set
This is my biggest quarrel with the Kyoto treaty is that the targets were set without regard for the individual circumstances of the nation by politicians who knew that they wouldn’t be around to have to ensure that they met them. Nor were they consistent across nations. Some nations promised just to limit their greenhouse gas increases (ie Norway), some promised to merely hold the line (ie France), and others promised bigger cuts (ie Canada and Germany). If that wasn’t enough, the circumstances of the individual nations is not taken into consideration.
Eastern European nations who began the 1990s with Soviet-era factories that were hugely inefficient and big polluters were shut down or renovated to reduce greenhouse gas emissions. Is it any wonder then that Bulgaria and Romania nearly halved its greenhouse gas emissions since 1990? [1,2] Or that Hungary and Poland dropped by nearly a third? [3,4] Nations such as Italy, without such inefficiencies to start with could not achieve such dramatic reductions (until the economy's bottom fell out in 2008 leading to a 10% reduction in greenhouse gases in a single year) .
As a comparison Canadians would be familiar with, Saskatchewan gets most of its electricity from coal fired power plants, while BC gets most of its electricity from hydroelectric projects. Would it be fair then to expect BC and Saskatchewan to both reduce their greenhouse gas emissions equally? Of course not, Saskatchewan could close its coal fired power plants and open natural gas ones and achieve dramatic reductions in greenhouse gas emissions. Whereas BC could not do so.
Also, no consideration was given to actual energy consumption. A nation that shutters all of its coal fired power plants only to import their electricity from a neighbouring country that didn’t promise dramatic reductions in greenhouse gas emissions hasn’t really reduced greenhouse gases, they’ve just moved them around.
One would hope that the representatives of the nations involved would take this into account when making commitments but again, how can we hold these politicians accountable for the promises they made when even they don’t expect to be around when the piper comes calling? Canada’s greenhouse gas emissions rose every year (except for two; 1990-1991 and 2000-2001) from 1990 to 2004.  Meanwhile, France actually remained relatively stable all the way since 1990  and is on track to meet their 0% increase target.
And what about the effect of circumstances beyond the control of the nation? Venezuela has been hit by numerous droughts in recent years that have crippled its hydroelectric capacity; if they switch to consuming more coal or natural gas to maintain their electric grid it would drive up their greenhouse gas emissions. Japan has had a number of earthquakes in the past which have shut down and/or damaged their nuclear reactors, forcing them to rely on fossil fuels more and more.
In short, Canada’s reported plan to withdraw from a flawed treaty should not come as a surprise to anyone and it doesn’t mean that Canada should be shunned from further climate change negotiations. If the world wants to make a true commitment to reducing greenhouse gas emissions, they need to bring every nation on board and set targets realistic and relevant to the nations themselves. Targets that are short term in nature so that the politicians who fail to meet them are around to shoulder the blame, and that adjustments can be made if circumstances make them unrealistic.
Even if you are skeptical of global warming and of the dire predictions that some global warming fearmongerers are making, reducing pollution can only be a good thing and reducing our dependence on fossil fuels is a necessary activity over the long term.
Again though, that's just my opinion.
 "GHG trends and projections in Bulgaria" European Environmental Agency, 2011 [pdf]
 "GHG trends and projections in Romania" European Environmental Agency, 2011 [pdf]
 "GHG trends and projections in Hungary" European Environmental Agency, 2011 [pdf]
 "GHG trends and projections in Poland" European Environmental Agency, 2011 [pdf]
 "GHG trends and projections in Italy" European Environmental Agency, 2011 [pdf]
 "National Inventory Report 1990–2008: Greenhouse Gas Sources and Sinks in Canada" Environment Canada, 2008 [pdf]
 "GHG trends and projections in France" European Environmental Agency, 2011 [pdf]