The UK has committed to reducing its carbon emissions to "net zero" by 2050, becoming the first G7 country to make such a pledge.
In one of her final acts as prime minister, Theresa May has heeded the advice of a government-commissioned climate change report to take action.
But how is this going to work, and what is going to change?
How does the new law work?
Under the current 2008 Climate Change Act, the UK is bound to reduce carbon emissions by 80% by the year 2050.
The new pledge will see this 80% target amended to "net zero".
In short, this means emissions from transport, farming and industry will either need to be completely cut, or to be offset by planting more trees.
The Committee on Climate Change (CCC), which carried out the research, has said the UK will need to look into more sources for renewable electricity, and potentially phase out new petrol and diesel cars by 2035.
A Road to Zero Strategy is already in place in the UK to stop the sales of new petrol and diesel cars, and the government predicts 70% of the country's electricity will come from "low-carbon sources" by 2030.
Carbon credits, which mark a country's allowance of carbon emissions and can be traded internationally, will also be available for use.
In a statement released Wednesday, the CCC stressed the amendment was "just the first step" toward the new target.
It added: "The target must now be reinforced by credible UK policies, across government, inspiring a strong response from business, industry and society as a whole."
Is there anything not included in the changes?
Yes. So far, international aviation and shipping has not been included in the new emissions target.
The CCC says that while there have been no formal moves to include these factors, the UK government has "acknowledged that these sectors must be part of the whole economy strategy for net zero".
Ongoing assessments and analysis on these areas are set to continue.
How are the those in the UK going to be affected?
The UK government has broken down the different effects and ways it will tackle climate change into three categories.
Businesses and universities
The UK sees itself at the forefront of the fight against climate change, which includes investing in the research and development of new technologies that help reduce carbon emissions.
It has so far pledged to invest £3 billion in "low carbon innovation" until 2021.
Businesses are also encouraged to make the most of "significant opportunities" for reducing emissions and wasted energy by carrying out energy audits.
You, us, them
Reducing carbon emissions can also begin at home.
The UK is encouraging everyone to "play a role in tackling climate change", by reducing food wastage, investing in reusable cups and reducing home energy.
To keep in line with the net zero target, households will eventually need to seek alternative energy methods, such as hydrogen or heat pumps.
Greg Clark, the Secretary of State for Business, Energy and Industrial Strategy, also suggests looking for low-carbon employment.
He says he wants to create millions of such jobs by 2030.
Tackling climate change can be a personal endeavour, but the UK says it's also beneficial to work with the local community.
It suggests that getting involved in community projects can not only help to reduce carbon emissions, but can also improve the quality of the air around us.
When will these changes start to happen?
Legislation for the net zero amendment to the Climate Change Act was put before the UK parliament on June 12.
But the real fight is going to take time, and will see periods of phasing practices out.
The CCC has also recommended separate targets to Scotland and Wales - the former is challenged with a net zero date of 2045, and the latter with a 95% reduction in greenhouse gases by 2050.
How have people reacted to this amendment?
Environmental groups are for the most part positive about the amendment, albeit some hope the changes could be implemented quicker.
The CCC said it was "delighted" by the UK's "major commitment" to working toward a cleaner environment.
It added: "This step will send a strong signal to other countries to follow suit – and will help to drive the global effort to tackle climate change required by the Paris Agreement."
Laurence Tubiana, the leader of the European Climate Foundation, said the amendment would serve as a "big contribution" to the upcoming UN climate change summit in September.
But some have been less optimistic.
The UK's Chancellor Philip Hammond warned May last week that such commitments would be costly to the UK, and could amount to more than €1 trillion.
Meanwhile, Green Party politician Caroline Lucas says the government has allowed for some "dodgy loopholes" in its law.
In a series of tweets, she asked why carbon credits had not been ruled out, and said some "real commitment" needed to be shown on bringing an end to fracking, talks on expanding London's Heathrow Airport, and investments in public transport.
She said: "Pledging a 2050 target is easy when its 30 years away."
"We shouldn’t be using dodgy loopholes to outsource our own responsibility to decarbonise at home."
"Actions speak louder than words."