Joao Pereira de Araujo stands in front of his home in Rio Branco in Brazil after the river Acre rose to a record high of 18.4 meters in March 2015. Nearly 100,000 residents were affected by the extreme flood. Photographer Gideon Mendel portrays flood victims worldwide to draw attention to their fates. His works are part of the show "Extreme. Environments" at Frankfurt's photo triennial, RAY 2018.

With his project "Drowning World," Mendel has been exploring the personal impact of climate change within a global context since 2007. "In a flooded environment, life is suddenly turned upside down, normalcy no longer exists and people need to adapt," he said. Francisca dos Santos is captured here outside her flooded home in Rio Branco, Brazil, in 2015.

The South African-born, London-based photojournalist started his "Drowning World" project when he documented widescale flooding in Yorkshire in 2007. "At that time I had small children and two questions occupied me for their sake: In what kind of world do we live; and what will the world look like in the year 2050?" he asked at an exhibition of the series in Zingst, in northern Germany.

Mendel's images show how water is the great equalizer that makes everyone the same. This photo of a photo found in Shirley Armitage's home in Somerset, England was one of many destroyed by flooding in February 2014. Mendel created another photo series called "Water Marks" that looks at how floodwaters have transformed very personal family photographs.

A water-damaged photograph from the home of Abdul Rashid in Kashmir, India, also in 2014. "I am fascinated by the arbitrary but shocking effects that floods have on precious keepsakes," says the photographer.

This is Gideon Mendel's personal favorite: It shows the baker Florence Abraham from Nigeria, who had a bakery with 50 employees and lost everything in the flood of 2012. The show "Extreme. Environments" can be seen until September 9, 2018 in the Fotografie Forum Frankfurt.

Unprecedented heat waves swept across the globe in 2017, leading to droughts, wildfires and even deaths. Australia started the year with temperatures near 50 degrees Celsius (122 Fahrenheit), the "Lucifer" heat wave brought the mercury above 40 degrees Celsius throughout Southern Europe in July and August and scorching heat hit India's most vulnerable people. Get ready for next summer...

Earlier this year, scientists realized that coral bleaching in Australia's Great Barrier Reef was worse than first thought. In some parts of the UNESCO World Heritage site, up to 70 percent of the coral has already been killed. By 2050, scientists have warned 90 percent of the reef could disappear. Rising sea temperatures and ocean acidification are the main culprits.

Armed conflicts are pushing millions of people to leave their homes or live in terribly precarious situations — and climate change is making it worse. A lack of natural resources increases the risk of conflict and makes life even harder for refugees. South Sudanese families, for instance, are escaping to neighboring countries like Uganda and Kenya — countries already suffering from drought.

From New Zealand to Spain, from California to even Greenland: the world has seen a nonstop year of wildfires. Global warming has been blamed for the increased fire risk, and in some countries that risk has turned into reality. Wildfires engulfed large areas of Europe's Iberian Peninsula, causing death and destruction, while firefighters in California have had no rest for more than six months.

Hurricanes Maria and Irma, which hit the Caribbean region in August and September, were two of the year's most damaging weather events. The list of deadly storms also included Ophelia in Ireland, Harvey and Nate in Central America and the US, and Xavier and Sebastian in Germany. Warming of the ocean surface has led to more evaporation, and that water may help fuel thunderstorms and hurricanes.

In July, one of the largest icebergs ever recorded separated from the Larsen C ice shelf — one of Antarctica's biggest — reducing its area by more than 12 percent. While calving icebergs in the Antarctic are part of a natural cycle, scientists have linked the retreat of several Antarctic ice shelves to global warming and are closely monitoring potential long-term effects.

Deteriorating air quality causes thousands of deaths around the world every year. India's capital, New Delhi, is one of the world's most polluted cities. In November, large parts of northern India and Pakistan were engulfed by a blanket of thick smog carrying harmful particulate matter. Schools were forced to close, and hospitals were full of people with respiratory problems.

The high levels of carbon dioxide in the atmosphere represent a major threat for our oceans, already in danger due to plastic pollution, overfishing and warming waters. Ocean acidification could make these waters — covering more than two-thirds of our planet's surface — a hostile environment for sea creatures. And without marine animals, entire ocean ecosystems are at risk.

Superstorms often trigger flash floods and mudslides. In late December, more than 230 people were killed when a storm hit the Philippines' second-largest island of Mindanao, a tragedy exacerbated by years of deforestation. In 2017, severe floods also hit countries such as Vietnam, Peru and Sierra Leone. European countries, including Greece and Germany, also felt the damaging effects of heavy rain.