A new study is blaming climate change for a surge in severe storms and weather-related wildfires around the world.
The scientists say that includes flooding in New Zealand last year.
Most years the Dungeness crab harvest in California is bountiful, worth close to $60 million.
But this year there may not be any harvest – high levels of toxic algae in the ocean make the crab too dangerous to eat.
The widespread algae bloom is because of unusually high temperatures in the Pacific.
"It's unbelievably warm," says Sarah Cohen, marine biologist at San Francisco Sate University.
"We have never had a warming event like this – the extent of it, the different contributing factors and how this going to play out this season leads scientists to have huge concerns."
Extreme heat events are one focus of today's report on the impact of climate change around the world.
The study found that in 2014, extreme heat waves, like one that gripped South Korea, were made worse by human caused climate change – things such as car emissions, burning coal and methane gas.
The report studied 28 extreme weather events around the world last year. Fourteen of those, including devastating floods in Australia and New Zealand, were found to be made worse in part by climate change.
But the impact of human activity can be complex, the report says. In the United States, record snowfall in the northeast and Midwest was not a result of climate change – rather, just cyclical weather patterns.
However, the study says the risk of severe wildfires in California is becoming more likely because of global warming.