Deena Robinson & Martina Igini / Global Commons
The world is grappling with a host of pressing environmental challenges that demand immediate attention and action. From climate change-induced disasters, biodiversity loss and plastic pollution to the rise of artificial intelligence, the 16 biggest environmental problems of 2026 paint a stark picture of the urgent need for climate change mitigation and adaptation. Earth.Org / January 9, 2026
- Food Waste
A third of the food intended for human consumption – around 1.3 billion tons – is wasted or lost. This is enough to feed 3 billion people. Food waste and loss account for approximately one-quarter of greenhouse gas emissions annually; if it were a country, food waste would be the third-largest emitter of greenhouse gases, behind China and the US.
Food waste and loss occur at different stages in developing and developed countries; in developing countries, 40 percent of food waste occurs at the post-harvest and processing levels, while in developed countries, 40 percent of food waste occurs at the retail and consumer levels.
At the retail level, a shocking amount of food is wasted because of aesthetic reasons; in fact, in the US, more than 50 percent of all produce thrown away in the US is done so because it is deemed to be “too ugly” to be sold to consumers- this amounts to about 60 million tons of fruits and vegetables.
- Melting Ice Caps and Sea Level Rise
The climate crisis is warming the Arctic more than twice as fast as anywhere else on the planet. Today, sea levels are rising more than twice as quickly as they did for most of the 20th century as a result of increasing temperatures on Earth.
Seas are now rising an average of 3.2 mm per year globally and they will continue to grow up to about 0.7 metres by the end of this century. In the Arctic, the Greenland Ice Sheet poses the greatest risk for sea levels because melting land ice is the main cause of rising sea levels.
Representing one of the biggest environmental problems our planet faces today, this is made all the more concerning considering that temperatures during the 2020 summer triggered the loss of 60 billion tons of ice from Greenland, enough to raise global sea levels by 2.2 mm in just two months.
According to satellite data, the Greenland ice sheet lost a record amount of ice in 2019: an average of a million tons per minute throughout the year. If the entire Greenland ice sheet melts, sea level would rise by six metres.
Meanwhile, the Antarctic continent contributes about 1 millimeter per year to sea level rise, which is one-third of the annual global increase. According to 2023 data, the continent has lost approximately 7.5 trillion tons of ice since 1997. Additionally, the last fully intact ice shelf in Canada in the Arctic recently collapsed, having lost about 80 square kilometres – or 40% – of its area over a two-day period in late July, according to the Canadian Ice Service.
Sea level rise will have a devastating impact on those living in coastal regions: according to research and advocacy group Climate Central, sea level rise this century could flood coastal areas that are now home to 340 million to 480 million people, forcing them to migrate to safer areas and contributing to overpopulation and strain of resources in the areas they migrate to. Bangkok (Thailand), Ho Chi Minh City (Vietnam), Manila (Philippines), and Dubai (United Arab Emirates) are among the cities most at risk of sea level rise and flooding.
- Ocean Acidification
Global temperature rise has not only affected the surface but it is also the main cause of ocean acidification. Our oceans absorb about 30 percent of carbon dioxide that is released into the Earth’s atmosphere. As higher concentrations of carbon emissions are released thanks to human activities such as burning fossil fuels as well as effects of global climate change such as increased rates of wildfires, so do the amount of carbon dioxide that is absorbed back into the sea.
The smallest change in the acidity scale can have a significant impact on the acidity of the ocean. Ocean acidification has devastating impacts on marine ecosystems and species, its food webs, and provoke irreversible changes in habitat quality. Once acidity (pH) levels reach too low, marine organisms such as oysters, their shells and skeleton could even start to dissolve.
However, one of the biggest environmental problems from ocean acidification is coral bleaching and subsequent coral reef loss. This phenomenon occurs when rising ocean temperatures disrupt the symbiotic relationship between the reefs and algae that lives within it, driving away the algae and causing coral reefs to lose their natural vibrant colours. Some scientists have estimated coral reefs are at risk of being completely wiped by 2050. Higher acidity in the ocean would obstruct coral reef systems’ ability to rebuild their exoskeletons and recover from these coral bleaching events.