The recent floods in Nigeria and other countries were caused by human caused climate change.

Floods that killed more than 600 people in Nigeria and more than 200 in Chad were the result of an extremely wet rainy season. Climate change has made the season, which runs from April to October, 20 percent more wet than it would have been without it.

The issue of "loss and damage", whether industrialized countries should pay less developed nations for the effects of climate change, is high on the agenda of the U.N. climate summit. Climate-related disasters like floods and heat waves are becoming more common in Nigeria and other African countries due to their relatively little carbon dioxide emissions.

The director of the Red Cross Red Crescent Climate Center said that the problem is a real and present one.

Dr van Aalst said that it was not up to scientists to tell the negotiators what to do. Climate disasters are not something that will happen in the future, according to the study. We need to deliver those solutions in countries that are vulnerable to loss and damage the most.

The analysis looked at two aspects of the seasonal rains this year, average rainfall for the entire season over a large drainage area, mostly in Chad, and spikes of extreme rainfall over weeklong periods in another drainage area, mostly in Nigeria.

The researchers used observational data as well as climate models to model both the current world and a world without emissions. The techniques used in this study have been peer-reviewed many times before.

The influence of climate change on the rains was determined by the researchers. Climate change made a high average rainfall 80 times more likely. The researchers found that climate change made the heavy rain more likely.

In the rainy season in West Africa, floods are not uncommon, but they were the worst in decades in Nigeria. Fuel and food distribution were disrupted and 1.5 million people were displaced in Nigeria.

Poverty, military conflicts and land-use changes are some of the factors that contributed to the disaster. Uncoordinated releases of water from a large dam made the flooding worse in Nigeria.

Friederike Otto is a climate scientist at Imperial College London. She said that a world without climate change would have been very rare.

With the planet continuing to warm, there will be more rainy seasons in the region.

The second analysis of the erratic and weak 2021 rainy season farther north in the Sahel was released by the Attribution group. The lack of rain resulted in food shortages in several countries.

Subsistence agriculture in the Sahel is dependent on the amount and timing of seasonal rain. The rainy season started later than usual, and there were some dry periods which slowed the growth of millet and other cereals.

A lack of reliable weather data is a common problem in less developed countries.

One of the researchers said that the study confirmed the importance of investing in and maintaining a network of weather stations. It's important to understand the influence of climate change on the region.