Arctic sea ice heavily contaminated with microplastics, and other nature and climate news you need to read this week

Scientists have discovered that algae in Arctic sea ice contains 10 times more microplastic particles than surrounding seawater.

The Melosira arctica algae, which grows beneath the Arctic sea ice, was found to contain alarming concentrations of microplastics, according to scientists from the Alfred Wegener Institute in Germany.

The research, published in the Environmental Science and Technology journal, focuses on the crucial role these algae play in the Arctic ecosystem. The Melosira arctica alga sits at the base of the food chain, which poses a threat to the surface and deep-sea-dwelling marine creatures that feed on it.

Throughout the Arctic spring and summer months, the algae grow beneath the sea ice in abundance, forming long cell chains that clump together as the ice melts and quickly sink thousands of metres to the sea floor. The dead cells are an essential food source for bottom-feeding marine life.

High concentrations of plastics found in the algae include polyester, nylon, acrylic and more, highlighting the urgent need for further investigation and action to mitigate the impact of plastics pollution on delicate Arctic ecosystems.

The El Niño weather pattern is likely to develop later this year and could contribute to rising global temperatures, according to the World Meteorological Organization.

After three years of the La Niña weather pattern in the Pacific Ocean, which often lowers global temperatures slightly, there's a 60% chance it will change to El Niño – its warmer counterpart – in May-July this year, the WMO said.

And that probability could increase to 70-80% between July and September, it added.

Speaking to reporters in Geneva, Wilfran Moufouma Okia, head of the WMO regional climate prediction services division, said there was no current estimate of how much El Niño would push up temperatures.

The world's hottest year on record so far was 2016, coinciding with a strong El Niño – although climate change has fuelled extreme temperatures even in years without the phenomenon.

During El Niño, winds blowing west along the equator slow down, and warm water is pushed east, creating warmer surface ocean temperatures.

Famine still stalks Somalia as East Africa's worst drought in 40 years has forced millions of Somalis to leave their homes. Five consecutive failed rainy seasons pushed the fragile nation to the brink of famine, and this year is unlikely to be much different.

Solar farm goes green by using more than 100 sheep to mow the grass twice a week. At the Rogane solar farm near the small town of Kamenica in eastern Kosovo, the bovine mowers eat the grass on the site, where more than 12,000 photovoltaic panels are installed, eliminating the need to spend on petrol-run lawnmowers.

Rainforest nations seek easier access to UN carbon credits, a financial scheme to reward them for preserving their rainforest and peatland ecosystems, which are vital to efforts to combat climate change.

Rich nations to meet overdue $100 billion climate pledge to developing countries this year, three years later than promised. Developing economies say they cannot afford to cut CO2 emissions without more support from the wealthy nations responsible for most of the greenhouse gases heating the planet.

India, China propose "multiple pathways" on cutting use of fossil fuels. They hope this will lead to a consensus within the G20 group to let countries choose a roadmap to cut carbon emissions instead of setting a deadline to end the use of fossil fuels.

How we can bring everyone along on the green energy transition? At the World Economic Forum's Growth Summit 23, funding climate technology to accelerate a green transition was under discussion. For a just energy transition, these technologies must also be made more available in the Global South, panellists agreed.

Unprecedented heat extremes "could occur in any region globally", new research warns. Developing countries that have avoided record-breaking heat for many decades are the least prepared for future “exceptional” heatwaves.

Japan sets historic example to save forests that protect coastal ecosystems vital to its fisheries. The lessons from Japan’s so-called "fish forests" could benefit nations the world over as the environmental crisis deepens.