UN oceans treaty a 'historic moment', and the other climate crisis stories you need to read this week

An agreement on a UN treaty to protect the high seas has been hailed as a "historic moment". The legally binding pact to conserve and ensure the sustainable use of ocean biodiversity has been under discussion for 15 years. It was finally agreed after five rounds of protracted UN-led negotiations that ended in New York.

"With the agreement on the UN High Seas Treaty, we take a crucial step forward to preserve the marine life and biodiversity that are essential for us and the generations to come," said Virginijus Sinkevičius, the European Union commissioner for the environment, oceans and fisheries. Sweden, the current holder of the EU's rotating presidency, said the agreement is the "most important international environmental deal" since the 2015 Paris Agreement on tackling climate change.

The treaty is seen as a crucial component in global efforts to bring 30% of the world's land and sea under protection by the end of the decade, a target known as "30 by 30" that was agreed in December. Economic interests were a major sticking point throughout the latest round of negotiations, with developing countries calling for a greater share of resources from the "blue economy".

Very little of the high seas is subject to any protection, with pollution, acidification and overfishing posing a growing threat. Environmental group Greenpeace says 11 million square kilometres of ocean needs to be put under protection every year until 2030 to meet the target. "The clock is still ticking to deliver 30 by 30. We have half a decade left, and we can't be complacent," said Laura Meller, a Greenpeace oceans campaigner who attended the talks.

Global energy-related emissions of carbon dioxide (CO2) hit a record high last year, according to the International Energy Agency (IEA). However the use of more clean technology such as solar power and electric vehicles helped limit the impact of increased coal and oil use.

Global emissions from energy rose by 0.9% in 2022 to a record 36.8 billion tonnes, IEA analysis showed. CO2 emissions from coal grew by 1.6%, with many countries turning to the more polluting fuel after Russia’s invasion of Ukraine sparked an energy crisis. Carbon emissions from oil rose by 2.5% but remained below pre-pandemic levels, the report said. Around half of the increase in oil-related emissions was due to a rise in air travel, which has rebounded since the pandemic.

Deep cuts in emissions, mainly from burning fossil fuels, will be needed over the coming years if targets to limit a global rise in temperatures are to be met, scientists have said. "We still see emissions growing from fossil fuels, hindering efforts to meet the world’s climate targets," IEA Executive Director Fatih Birol says.

Lower output from nuclear power plants and extreme weather events including heatwaves also contributed to the increase in energy-related emissions. However these were partly offset by a rise in renewable power sources, energy efficiency measures and electric vehicles. These avoided an additional 550 million tonnes of CO2 emissions last year, according to the IEA.

“One million species teeter on the brink of extinction, due to habitat destruction, fossil fuel pollution and the worsening climate crisis. We must end this war on nature,” UN Secretary-General António Guterres said on World Wildlife Day. The UN is calling for bolder action as well as more effective partnerships to protect biodiversity.

The world cannot meet its goal to limit global temperature rise to 1.5°C unless it protects the Amazon rainforest, US Climate Envoy John Kerry said during a visit to Brazil. Scientists say protecting the Amazon is vital to tackling the climate crisis because of the vast quantity of greenhouse gases its trees absorb.

Argentina is being hit by a late-summer heatwave, with many places setting record temperatures for the month of March. The country has been hit by drought since last year, which has impacted its key soybean, corn and wheat crops.

A heatwave in northern and central India is threatening to damage grains and dent the country's wheat production for a second consecutive year. The maximum temperature in some wheat-growing areas jumped above 39°C for a few days in February, nearly 10°C above normal.

French President Emmanuel Macron has promised €50 million ($52.9 million) to a new global scheme to reward countries for protecting their forests and biodiversity. The pledge was announced at the end of the One Forest Summit in Gabon that aimed to renew targets for the preservation and sustainable management of the world's forests.

The UK has launched a new action plan to protect biodiversity and ecosystems from invasive non-native species. The government says the encroachment of non-native species is one of the main drivers of biodiversity loss globally.

Danes should replace two-thirds of their meat intake with vegetables and other plants as part of efforts to reach the country's ambitious climate targets by the end of the decade, the government's independent adviser says. A tax on food items that are harmful to the climate was among the key recommendations put forward by the Danish Climate Council.

Extreme weather caused by the climate crisis could cost Germany up to €900 billion ($960 billion) in cumulative economic damage by mid-century, according to a new study. It says extreme weather events have already cost the country at least €145 billion between 2000 and 2021, with €80 billion of this coming in the past five years.

Canada's Rideau Canal Skateway, the world's largest natural ice skating rink, will not open this season for the first time due to a lack of ice. Its operator is blaming the closure on the climate crisis.

Last year marked the third consecutive La Niña year – a highly unusual trends that has only occurred three times since records began in the 1950s. Changes in La Niña and El Niño add up to an uncertain outlook for the future, say these climate scientists.

Winter in the northern hemisphere has been marked by unusual temperature swings. These weather patterns have been attributed to the climate crisis.

US Department of Energy scientists have developed a new method of cooling and heating that is more climate-friendly than existing methods. The innovation could help countries meet climate targets.