View From Down Under

The agreement reached in Copenhagen falls far short of the goal of a binding treaty limiting greenhouse gas emissions.  It is a ‘statement of intent’ to try to limit global warming to no more than 2°C, and a plan to help developing nations deal with climate change over the next 10 years.

Despite the President’s assertion that this is a step towards a legally binding treaty, it is more a recognition that a binding treaty to limit emissions is politically impossible – and likely always will be.

A binding treaty has a number of difficulties, not the least of which is that it is impossible to have a global binding treaty without global enforcement, and most governments are reluctant to relinquish any part of their sovereignty (just ask Chinese Premier Win Jiabao).

There are also some complex economic issues with developed vs developing countries.  How much should developed countries pay to developing countries to make up for the greenhouse gases they (developed countries) have already emitted?  How much will reducing emissions restrict economic development?  How can the US or Europe ask to limit new power plants in other countries when their own power production is emitting so heavily?  Should developed countries ‘share’ green technology with developing countries?  Because any compromise will be a political negotiation, it is certain to allocate these costs unfairly.  Even if fairness is somehow achieved, it will be perceived as unfair.  It is very difficult to ask Americans to send money or technology to India or Indonesia so that they can effectively become more competitive in the world economy.

But even a ‘binding’ treaty will be less than binding.  There will continue to be incentives to cheat, and the political reality is that many countries will do so if it is in their interest.  In that environment, a ‘statement of intent’ is a good outcome.

So it looks as though global warming will continue, and probably accelerate, for at least the next decade.

There is hope that things will change.  Europe, the US, and even China are putting large chunks of R&D investment into clean energy technologies.  Over time, it is likely that some of these will become cost competitive, particularly if carbon emissions are taxed or regulated to account for the externality of global warming.

The biggest emitters are China, USA, EU, Russia, India, Japan, and Brazil.  Concerted efforts by this group to reduce emissions is likely – all of them are publicly proclaiming this commitment.  If the rhetoric is indeed followed by reality, I am optimistic that we will see a reduction in emissions in the next ten years.

Whether it is enough to limit warming to another 2° remains to be seen.

Popularity: 61% [?]

Over that last few years the percentage of Americans who believe in human caused global warming has shrunk, even as the evidence for it has grown.  If the heat and noise of the debate has got you questioning, here is a small sample of the evidence.

First, the things we can know with certainty.

The global climate system has warmed over the last 100 years.  This is unequivocal, and supported by increases in global air and water temperatures, widespread melting of snow and ice, and rising global average sea level.  Yes there are yearly variations around the trend line, and some years are cooler than the previous year, but the trend is real.  (This data comes from NASA Goddard Institute)

The levels of CO2, methane, and nitrous oxide have increased dramatically in the last 100 years.  CO2 levels have increased roughly 35% over the last 50 years.  Methane has increased 48%, and nitrous oxide has increased 18%.  All of these are substantially above the natural range over the last 650,000 years as determined by ice core analysis.

These increases are due primarily to human activity.  Use of fossil fuels, agriculture, and change in land use are the primary contributors to the increase.

The levels of greenhouse gases are highly correlated with increasing global temperatures – and have been for millennia.  The data below comes from analysis of Antarctic ice cores.

These are facts regardless of whether you or I believe them to be facts.

There are other things we can know with a very high degree of certainty.

Climate models have been around for nearly 50 years, and are continuously getting more accurate as more data arrives.  These models are developed both independently and collaboratively by scientists in many countries.  None of these models are able to predict the current increase in global temperatures and sea levels without taking into account the man-made increases in greenhouse gases.  There is a very high degree of certainty that global warming is the result of human activity.

The big unknown is how much more the climate will change in the future.  As you can imagine, this will depend on the level of greenhouse gases we emit.  Estimates for temperature change by the end of this century range from alarming (1.8°C assuming global population peaks mid century and a rapid shift to clean technologies) to catastrophic (4.0°C if economic growth continues to be driven primarily by fossil fuels).

Despite all the certainty surrounding global warming,  the impact of continued climate change on human endeavours is unknown.  Scientists can estimate impacts on sea levels, precipitation, surface temperatures, and more, but calculating the cost of global warming in economic, social, or environmental terms has so far proven to be very difficult.  As has estimating the cost of avoiding further climate change.

But there is no doubt that global warming is real and will continue for some time.

Popularity: 75% [?]

Is smoking a leading cause of lung disease?  Do El Nino episodes cause weather changes?  Did widespread use of DDT cause major reduction of bird and fish populations in affected areas?

If a survey asked these questions today, the results would show an overwhelming majority of people in agreement.  Among scientists, there would be almost no doubters.  However, each of these propositions was initially met with strong, vocal, and emotional reactions from skeptics – many of whom owed their livelihoods and reputations to denying them.

Today, there is virtual unanimity among scientists about global warming.  The National Academy of Sciences, American Chemical Society, Crop Science Society, and many other scientific organizations have issued public statements confirming that global warming is occurring and is the result of human activity.

In spite of this, a recent survey by the Pew Research Center shows the number of Americans who believe there is solid evidence of global warming has actually dropped in the last three years.  A majority of Americans simply do not believe the scientific organizations.

Here is the data by political affiliation.  Belief in global warming has declined across the board, but the decline has been dramatic among Republicans.  Nearly half of the Republicans who in 2006 believed the earth was warming no longer believe so.

Just shows what can happen when a scientific issue becomes a political and emotional one.  It is clear there are a number of highly effective communicators in the US whose livelihood and reputation depend on debunking global warming.  As Upton Sinclair wrote:  ”It is difficult to get a man to understand something, when his salary depends upon his not understanding it”.

In the midst of the Copenhagen climate change meetings, I’ll be posting a few thoughts on climate change.  Next post will be fairly heavy on data.  In the meantime, I encourage you to look at some data yourself.  A couple of good places to start are the IPCC Summary and the National Academy of Sciences climate change report.

Popularity: 72% [?]