Officials in California say a wildfire that began burning more than a week ago has become the largest in the state's history.

Researchers at the University of California say the climate conditions that make such large fires possible come earlier and last longer. Officials are warning residents to brace for more. "What seems like we should be in the peak of fire season historically is really now,the kind of conditions we're seeing really at the beginning. "

Forest fires are raging in Europe too. The deadliest wildfire in Greece in recorded history killed more than 90 people last month. Even forests in northern countries such as Sweden and Latvia were caught in flames. Many European and Asian cities are battling heat waves and reporting the highest temperatures on record. Extreme heat has had its effect on agriculture. Farmers are harvesting crops earlier than usual and prolonged droughts have reduced the quality and quantity of fruits and vegetables.

Heat is killing fish in a section of the Rhine River in Switzerland. The Swiss Army dropped emergency water supplies for animals in the water region farms. "The army services are provided free of charge because we are in what is considered a disaster situation. "

A new study says the global warming targets set at the 2015 Paris Climate Agreement may not be able to stop these harmful rises in temperature. Countries agreed to make voluntary efforts to keep the world's average temperature from rising two degrees Celsius above what it was before the Industrial Revolution.

The latest study, conducted jointly by the Australian National University, the University of Copenhagen and other institutions,says even if signatories adhere to the agreement, processes such as polar ice melting and methane-releasing from the sea floor may increase the temperature on earth by four to five degrees in the future, making some parts of it uninhabitable. In the meantime, unusual heat waves currently hitting Europe and Asia are expected to become common.

Zlatica Hoke, VOA News, Washington.