The Democratic Party looks to have taken control of the United States House of Representatives after this week's mid-term elections, delivering a blow for President Donald Trump's legislative agenda and prompting hope in Washington, D.C., of renewed progress on tackling climate change.

However, while some votes have yet to be fully counted, the Republican Party looks to have retained control of the Senate as expected, meaning a divided Congress in Washington that could lead to more legislative gridlock after one of the most bitterly fought elections in recent history.

Nevertheless, Democrats hailed the elections as a key win for the party, which gained more than 30 seats in the House, securing a House majority for the first time in eight years. The shift should enable Democrats to block Trump appointments, stifle his legislative ambitions, investigate his business dealings and even open up the president to impeachment proceedings.

The changes on Capitol Hill also should have significant implications for climate policy and the green economy. A Democratic-controlled House means the president could struggle to pass more of his hard-line policies on international trade — which previously have seen tariffs placed on imported solar cells and modules, for example — and could limit his ability to appoint more climate skeptics to key federal positions. Meanwhile, Democrats are set to take over the chairing of key House committees covering science and the environment, many of which have been led by climate-skeptic Republicans for years.

Democratic National Committee chairman Tom Perez reportedly hinted that he planned to push for stronger climate action at the U.S. Environmental Protection Agency (EPA), which since Trump took over the presidency has sought swinging cuts to environmental regulations, such as on car fuel efficiency and the Obama-era Clean Power Plan.

The Chairman of the @DNC, @TomPerez just said on national television that they're going to make sure the EPA administrator "understands climate science".

I volunteer to be part of that task force!— Michael E. Mann (@MichaelEMann) November 7, 2018

This week's elections also mean at least 100 women will likely be elected to the House, including Democrat Alexandria Ocasio-Cortez, who repeatedly has made strong calls for greater climate action at a federal level since her shock win as the party's candidate for New York City's 14th district seat earlier this year.

Ocasio-Cortez, the youngest woman elected to Congress at 29, is one of a group of Democrats joining the House who have backed a progressive "Green Deal New Deal" platform, which aims to deliver a radical spending plan to rapidly shift away from fossil fuels and prepare the United States for the impacts of climate change.

But the Democrat's almost certain victory in the House is only one part of the story from the midterms, which saw both gains and setbacks for the low carbon agenda across the 35 Senate seats and 36 state governorships that also were up for grabs.

Hopes of cross-party climate action, such as through an oft-mooted carbon tax, suffered a setback from the electoral losses of several Republican members of the House bipartisan Climate Solutions Caucus, including the group's GOP founder, Carlos Curbelo. Earlier this year, Curbelo had proposed an ultimately unsuccessful carbon tax bill which failed to gain support among much of his party, and his loss puts the future of the caucus "in doubt," according to Mother Jones.

Moreover, Washington state voters rejected a proposed carbon tax that would have mandated companies using or selling fossil fuels to pay $15 per metric ton of carbon, a figure set to rise in future years. It would have been the first direct levy on CO2 in the United States.

Similarly, voters in Colorado look to have rejected a ballot measure that would have imposed restrictions on where oil and gas companies could drill and frack, according to The Hill.

Yet there was also more positive green economy news from Colorado, where Democratic Congressman Jared Polis was elected governor. Polis has promised the state will run on renewable power by 2040, meaning it would phase out fossil fuel generation even faster than California and Hawaii, which both recently have introduced similar goals for 2045, according to reports from Climate Home.

And veteran climate campaigner and journalist Bill McKibben hailed a clean energy initiative in Portland that looks to have secured enough support from voters at the ballot. The proposal would place a tax on large businesses to fund clean energy programs and job training.

Whoa! The Portland Clean Energy Initiative is going to pass! Taxes big box retailers to put up clean energy in poor neighborhoods. A win on many counts! Thanks to all who organized! @350_PDX https://t.co/UmcnZ4YPLQ

— Bill McKibben (@billmckibben) November 7, 2018

Some media commentators, however, suggested it had overall been an "abysmal night" for energy and climate ballot initiatives, although others were quick to counter that Democrat success at state level elections across the United States could make a positive impact.

It was an abysmal night for supporters of energy & climate ballot initiatives. Arizonans rejected a renewable energy increase. Washingtonians rejected a carbon price. Nevadans rejected competitive markets. And Coloradans rejected fracking limits. That's a pretty sweeping defeat.

— Stephen Lacey (@Stphn_Lacey) November 7, 2018

Meanwhile, some key climate skeptic senators in the Republican Party looked to have lost their seats,such as California's Dana Rohrabacher, who previously had claimed CO2 "is not a pollutant," among other comments. Nevertheless, a number of GOP stalwarts retained or gained Senate seats, including Ted Cruz, who looks to have won a closely fought election in Texas.

Overall, the Republicans lost the popular vote in the Senate by a large margin, but the results mark the first time in more than a century that an incumbent U.S. president has won additional Senate seats in a mid-term election. The contrasting results in the Senate and House have left analysts divided as to whether the outcome strengthens or weakens Trump's prospects going into the 2020 election.

On the campaign trail, Trump continued to avoid settling on a clear position as to whether climate change is a man-made, but his pro-coal and anti-climate action rhetoric still seems unlikely to shift as he gears up for the 2020 presidential election, which could be crucial for deciding whether the United States is able to formally exit the Paris Agreement, as is Trump's current plan.

Received so many Congratulations from so many on our Big Victory last night, including from foreign nations (friends) that were waiting me out, and hoping, on Trade Deals. Now we can all get back to work and get things done!

— Donald J. Trump (@realDonaldTrump) November 7, 2018

With a divided congress and a president who is apparently loved and loathed across the country, the next two years are likely to remain fraught for U.S. politics. But while Trump's more excessive moves against climate and environmental action could well be curbed by a Democrat-controlled House, a concerted low carbon agenda in Washington also remains highly unlikely. If the latter is to happen any time soon, it likely will rest upon a president far more cognizant of the risks and opportunities posed by climate change making it to the White House in two years' time.