The Swiss people have voted yes to a new climate law that will see the country cut net greenhouse gas emissions to zero by 2050.
A majority of 59 per cent of voters approved the government's Climate Protection Targets, Innovation and Strengthening Energy Security Act on 18 June.
Almost three-quarters of people (74 per cent) backed it in the canton of Geneva, following a record-breakingly hot spring for the wealthy European nation.
"The Swiss understood that the climate law is essential to take a first step and inscribe in Swiss law a clear objective for 2050," said Green Party MP Céline Vara. "When you have a clear objective, you can then put in place the necessary measures."
Speaking on the RTS TV channel yesterday, she expressed gratitude that people listened to the advice of experts, and not the "lies" posted through letterboxes by opponents.
The new law was accepted by parliament in September last year, but opposition from the right-wing Swiss People's Party meant that it was put to a referendum.
Switzerland is particularly vulnerable to climate change; its temperature was already 2.5°C warmer in the last decade to 2022 than the pre-industrial average.
Swiss glaciers experienced record melting last year, losing more than 6 per cent of their volume. And this Spring saw extreme swings between heavy downpours in central and eastern parts, and drought in the south.
The Climate and Innovation Act - otherwise known as the Climate Protection Law - will bind Switzerland to climate neutrality by 2050. This means that its greenhouse gas emissions cannot exceed the quantity of harmful gases sucked in by its CO2 sinks - from forests to carbon capture technology.
Switzerland currently imports around three quarters of its energy, including all fossil gas, from abroad.
The government says that "these fossil fuels will not be available indefinitely and they place a heavy burden on the climate. In order to reduce environmental pollution and dependence on other countries, the Federal Council and Parliament want to reduce the consumption of oil and gas."
The new law will financially incentivise replacing oil and gas with clean energy, with the government pledging 2 billion francs (around ?2 billion) over 10 years towards the transition.
People who replace their fossil fuel dependent heating systems will benefit, as well as companies investing in "climate-friendly technologies".
"The aim is to produce more energy in Switzerland," the government adds, describing the act as an indirect counter to the 'Glacier Initiative' - a separate proposal to ban fossil fuels.
It had the support of all other major parties, but the People's Party branded the act an "electricity sinkhole" that will hurt the economy.
Switzerland's scientific community voiced its strong support for the Climate Protection Law.
Writing for ETH Zurich University, professor of climate physics Reto Knutti called it an "important step forward in the area of climate and energy policy" after "years of political stalemate".
Knutti is one of more than 200 scientists at Swiss universities who signed a public statement in support of the proposal, which they believe will make the country stronger.
"When it comes to climate change, research can no longer really afford to remain apolitical," he wrote.
Greenpeace Switzerland welcomed the result of the referendum.
"This victory means that at last the goal of achieving net zero emissions will be anchored in law. That gives better security for planning ahead and allows our country to take the path toward an exit from fossil fuels," said Georg Klingler, an expert on climate and energy at the NGO.