All major industrialized countries are failing to meet the pledges they made to cut greenhouse-gas emissions

See Prove Paris was more than paper promises. Published in Nature. Excerpts:

"Emission rates are falling in almost all advanced industrialized countries. But the declines are too slow to meet the pledges that governments made in Paris (see 'Climate shortfall'). Although the general story is the same, the details differ for each.

For example, in 2015, the administration of former president Barack Obama pledged to cut emissions in the United States to 26–28% below 2005 levels by the year 2025. Yet the country was probably only ever on track to cut its emissions by 15–19%. The energy markets are, of their own accord, substituting natural gas for coal; and policies that push renewable energy and energy efficiency are playing a part³. The assumptions about maximal carbon sequestration from forestry, which the US government submitted to the secretariat of the United Nations Framework Convention on Climate Change, can best be described as heroic. Even when these are combined with optimistically low assumptions about energy demand and the cost of clean energy, emissions are likely to decline, at most, to 23% below 2005 levels by 2025.

Under Trump, the gap between what was promised and what will be achieved has widened as the federal government seeks to revoke the US Environmental Protection Agency's Clean Power Plan, to roll back limits on the emission of the potent greenhouse gas methane and to reverse energy-efficiency policies⁴. Many companies, cities and states in the United States have vowed to keep cutting emissions but, for now, most of those are still just claims.

Japan pledged to cut emissions by a similar percentage to the United States: 26% below 2013 levels by the year 2030. But the Japanese economy is already more efficient than that of the United States — each dollar equivalent of economic output in Japan requires 40% less energy, according to the International Energy Agency. Making an efficient system even more frugal will require a massive effort. The costs of meeting Japan's pledge are high¹, and they are poised to increase to levels that are unsustainable politically for industries that must be competitive worldwide. Programmes aimed at moving quickly to the most efficient equipment in the steel industry, for example, will force retirement of capital stock much faster than makes sense for the market.

In Japan, as in all industrialized countries, electricity is pivotal to efforts to control emissions. All told, Japan's pledge and associated policies would reduce electricity consumption by 17% below the level expected without new policies by the year 2030 — despite the fact that more sectors such as transport will use electricity.

In addition, the Japanese government is unlikely to meet its aim to supply 20–22% of electricity from carbon-free nuclear power by 2030; our analysis suggests that 15% is more likely. Today, just 5 of the country's 42 nuclear reactors are producing electricity. Efforts to restart more are mired in political and regulatory issues in the aftermath of the Fukushima Daiichi nuclear-reactor disaster.

The EU also faces a big gap between words and actions."

"Other advanced industrialized countries present a similar story of public swagger and lagging implementation."

"Underlying these gaps in action is a powerful political logic. Climate change is an issue of huge public interest, especially in countries in which governments feel they must be seen to lead on global solutions. It is easy for politicians to make promises to impatient voters and opposition parties. But it is hard to impose high costs on powerful, well-organized groups. No system for international governance can erase these basic political facts. Yet the Paris agreement has unwittingly fanned the flames by letting governments set such vague and unaccountable pledges.

Most pledges are almost silent on the range of policies being used, making it difficult to discern which are actually effective. The EU, for example, submitted little information about the complex pledge-implementation process that is already under way. The gap between promise and action is especially large for the strategies that governments are using to boost energy efficiency, for which the real costs are often opaque. Equipment prices can be easily assessed but these are frequently only a fraction of the total deployment costs.

The pledges are impenetrable in other ways. Even the Obama administration, which vowed to set a high standard for openness, did not disclose the assumptions it used to model future emissions. More information is needed to evaluate the plausibility of carbon sequestration by forests, projected outcomes of climate policy and business-as-usual market trends — especially in light of the change in US leadership.

Accountability is crucial to bottom-up diplomacy, yet inconvenient for governments that are focused on looking good. It also makes academic research more useful. For example, academics have built an array of energy models that compute the costs of controls. These can be central in the policy debates about how much nations are willing to spend to address climate change, as well as how such resources can be deployed most efficiently. However, the models rest on a huge number of assumptions about the design and implementation of policies, the availability of technologies and the structure of the economy that affect projected costs manyfold."