Climate policymakers need to judge domestic measures by their effect on emissions worldwide, including whether cuts at home cause increases elsewhere, according to a recording published by the Brookings Institution.
The test goes beyond whether a policy reduces emissions within the country that adopts it. Policies can also affect emissions abroad, both by shifting pollution elsewhere and by making clean energy technologies cheaper and more widely available.
The remarks appeared in “Cut demand or cut supply? Rethinking climate policy,” published Nov. 3. The supplied remarks do not identify the speaker by name, role or institution.
“Climate is a global problem,” according to the Brookings Institution recording. The starting question for a policymaker is how measures adopted at home affect emissions everywhere, rather than looking only at what happens within national borders.
Carbon dioxide has the same effect on the climate regardless of where it enters the atmosphere. The remarks used emissions from a vehicle’s tailpipe in Chicago and a factory smokestack in Paris to explain why location does not change the resulting climate damage.
That makes the effect outside a country part of the assessment of its domestic climate measures. A reduction at home is only part of the picture if the same policy also changes the amount of carbon dioxide released elsewhere in the world.
One concern is emissions leakage, when measures to cut emissions in one place cause them to rise elsewhere. Policymakers need to design local measures to avoid inadvertently increasing emissions abroad while seeking reductions within their own countries.
The discussion then turned to China’s support for clean energy over the past couple of decades. Public policies there have helped lower costs and improve technologies used in solar power, batteries and electric vehicles.
Those changes have encouraged the use of clean energy technologies beyond China. Their adoption has spread across rich countries as well as low- and middle-income countries, extending the effects of China’s policies beyond its own emissions.
The remarks linked that wider adoption to reductions in emissions around the world. The example put the availability and cost of technology alongside the risk of shifting emissions abroad as considerations when assessing what domestic climate policy achieves.
The remarks gave no numerical estimate for the emissions reductions attributed to China’s policies or for the scale of emissions leakage. They also left open which specific measures policymakers should choose to reduce emissions worldwide.
