Some questions and answers about US' emissions, climate plans

The United States, the world's second largest emitter of greenhouse gases, has pledged to halve its emissions by 2030 compared to 2005 levels — but so far is failing to stay on target, analysts say.

Here are some questions and answers about America's emissions and its climate plans:

How much does the US emit?

In 2021, the United States emitted 6.28 billion tonnes of carbon dioxide equivalent — a measure of all greenhouse gases — according to Climate Watch, citing data from the Potsdam Institute for Climate Impact Research.

That makes it currently the second biggest emitter globally, behind China.

But, when historical emissions are factored in — that is, cumulative emissions since 1850 - the United States becomes the clear leader.

US emissions peaked in 2007 and have been falling ever since.

Where do the emissions come from?

Transportation is the largest contributor to US emissions, according to the Environmental Protection Agency (EPA), accounting for 28 percent of the country's greenhouse gases in 2021.

It is followed by electricity generation, which accounts for around a quarter of emissions.

After that comes: industry (23 percent), the commercial and residential sectors (13 percent), and finally agriculture (10 percent).

In 2022, around 60 percent of US electricity production came from gas- or coal-fired power plants, the highest emitters, according to the US Energy Information Administration (EIA).

The remainder came from renewable energies (21.5 percent), and nuclear power (18 percent).

What are America's climate targets?

In 2021, US President Joe Biden pledged to reduce emissions by 50-52 percent by 2030, compared to 2005 levels.

This target is part of the Paris Climate Agreement, and should enable the world's leading economy to achieve carbon neutrality by 2050.

For the energy sector specifically, Biden wants electricity production to reach carbon neutrality by 2035.

Is the US on track?

No, say experts - though some progress is being made.

Biden's administration recently passed several laws with far-reaching consequences, including a major infrastructure modernisation plan in 2021 which included, for example, the construction of a network of charging stations for electric vehicles.

Last year Biden also passed the "Inflation Reduction Act" (IRA), which brings $370 billion dedicated to the environment in the shape of an energy transition project designed to free up investment in clean energies.

The government has also taken regulatory action via the EPA - such as plans to reduce methane emissions from the oil and gas industry, and to require certain power plants to capture the majority of their CO2 emissions by 2030.

But according to a recent report by the UN Environment Programme (UNEP), these efforts ar e not enough: at this rate, the United States will not meet its 2030 emissions targets.

An analysis by the Rhodium Group earlier this year showed that those two major pieces of legislation Biden has passed will reduce emissions by 32-42 percent by 2030 – still a long way from the 50 percent target.

The report says there is still a chance of meeting that target – but it won't be easy, requiring further ambitious measures to be taken both at the federal level and within the states.