GOTHIC, Colo. – David Inouye is an accidental weather scientist.
More than 40 years ago, the biologist at the University of Maryland began studying when wildflowers, birds, bees and butterflies appeared for the first time every spring on this mountain.  Currently, plants and animals arrive at the Rocky Mountain Biological Laboratory one or two weeks earlier than they were 30 years ago. The robins that used to arrive in early April now appear in mid-March. Marmots end their winter sleep earlier and earlier.
"If the weather did not change, we would not see these kinds of changes happen," Inouye said as she stood in a bed of wildflowers that are appearing on the first day of May when the marmots sniff nearby.
It has been 30 years since much of the world discovered that global warming had arrived. On June 23, 1988, NASA scientist James Hansen testified before Congress, explaining that gases trapped by the burning of fossil fuels were raising temperatures.
But it turns out that climate is not the only thing that is changing: nature itself is, too. That's the image painted by interviews with more than 50 scientists and an Associated Press badysis of data on plants, animals, pollen, ice, sea level and more.
You do not need a thermometer or a rain gauge to notice climate change, and you do not need to be a scientist to see it.
The evidence is in the blueberry bushes at Walden Pond by Henry David Thoreau, the dwindling population of polar bears in the Arctic and dying corals around the world. Scientists have documented 28,800 cases of plants and animals that consistently respond to temperature changes, according to a 2008 study in the journal Nature.
"Nature is extremely sensitive to temperature and nature reacts to warmer temperatures," said Boston University biologist Richard Primack. "The dramatic change is happening right in front of us."
In the 1850s, Thoreau drew the Walden Pond map when it blossomed. At that time, it happened around May 16, on average. In the last 10 years, it was averaged on April 23. Primack started tracking cranberries there in the early 2000s, so he can not say specifically how much of the previous flowering was due to temperatures in the past 30 years, but it's about a third of that is.
In 1983, postman John Latimer began recording when birds, chipmunks and butterflies emerged, when trees and plants bloomed and when they changed color and dropped leaves in northern Minnesota. Spring comes before, he discovered. But it is not consistent; There are some really late years interspersed, creating a roller coaster effect.
Beginning about 30 years ago, the overall growth season throughout the northern hemisphere "abruptly changed to a new normal," with earlier springs and subsequent drops, said Mark Schwartz, a geographer at the University of Wisconsin-Milwaukee. In the lower 48 states, 2012 was the first recorded growth season until it was exceeded in 2017.
In the US. The first frost of autumn is occurring about nine days on average later than 30 years ago, while The Last Frost of Spring is occurring almost four days before, according to the National Oceanic and Atmospheric Administration.
That means that the growing season in the middle is almost two more weeks. And some of the things that are growing make us sneeze and suffer.
The high days of ragweed throughout the United States increased from 1990 to 2016, according to a study by the United States Department of Agriculture Lewis Ziska. In Kansas City, the number of days of high pollen jumped from 58 to 81.
"Allergies and asthma are on the rise … Climate change is not the only reason, but it contributes," said Dr. Howard Frumkin, former head of environmental health at the Centers for Disease Control and Prevention and now at the Wellcome Trust in London. Frumkin said ragweed and poison ivy trigger more potent allergic reactions with higher levels of carbon dioxide.
Some of the most punished places on Earth are underwater. Coral reefs are sensitive to warmer waters, and there is no reef on this planet that has escaped global warming unscathed, said Mark Eakin, coordinator of coral reef monitoring for the National Oceanic and Atmospheric Administration.
Coral reefs around the world have suffered great damage, "Eakin said." Many of them are shadows of what they have been before 1998. "
There was no mbadive global coral bleaching, when they bleach due to heat stress and die frequently, until 1998. Another blow in 2010 and after 2014 to 2017 was the largest global mbad bleaching of all, devastating Australia's Great Barrier Reef, Eakin said.
The melting ice has turned polar bears into the poster of climate change, and studies show that their survival rates, reproduction rates and body weight are decreasing in most of the Arctic, said Steven Amstrup, senior researcher at the polar bear in the United States. The United States Geological Survey and now the chief scientist of Polar Bear International In parts of Alaska, Amstrup discovered a 40 percent drop in population since the mid-1990s.
When A mstrup began studying polar bears in Alaska was tracking the resurgence of the animals of widespread hunting in the 1950s and 1960s. But from the late 1990s they began to lose their habitat and "we were not seeing so many big old bears "
Ornithologist George Divoky, in his 47th summer on Cooper Island, Alaska, to study shorebirds, is another accidental weather scientist.
"In 1988, things started to get strange," said Divoky. In the years that followed, seabirds such as the black spider began arriving earlier, laying eggs before and not surviving as well, he said, blaming the warming.
In 1989, Divoky counted 220 pairs of birds. Last year, there were 85 pairs, and two thirds of the chicks died.
"I was just studying birds," said Divoky. "I'm not proud that I can document the end of a seabird colony in the Arctic."
Katharine Hayhoe, a climate scientist at Texas Tech, has heard non-scientists accusing the government or researchers of manipulating temperature data to show the warming. There's no way to cook the books, she said; Nature is transmitting a clear signal about climate change.
"If you do not trust thermometers, throw them away," Hayhoe said. "All we have to do is see what is happening in nature."
AP data journalist Nicky Forster contributed to this story from New York. Follow Seth Borenstein on Twitter at @borenbears. Your work can be found here.
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