Christy and his colleague Roy Spencer were the first researchers to analyze temperatures in the troposphere, a lower atmospheric layer, using satellite records. They identified cooling — not warming — in recent decades, a surprise in an era of global warming. But when others, including Carl Mears, a senior research scientist at the research company Remote Sensing Systems, reexamined Christy’s work in the early 2000s, they found errors that when corrected revealed warming in the troposphere. Christy acknowledged the error, according to the New York Times. As recently as 2017, multiple scientists corrected or raised concerns about how Christy’s team was analyzing satellite data.

In congressional testimony on climate change, Christy has touted his own estimates of atmospheric temperatures despite his record of mistakes, drawing complaints of “political grandstanding” from NASA climate scientist Gavin Schmidt in a 2016 analysis finding distortions in the data that Christy presented to lawmakers.

A broad scientific consensus now exists that the Earth's climate has warmed over the last century and will continue, so Christy’s skepticism toward climate models, which have been proven roughly true in their predictions, has other climate scientists critical of his new EPA role.

“He has made many statements before Congress and elsewhere that are at odds with the scientific evidence because of his personal value system. He is not an appropriate appointee for this advisory panel, unfortunately,” said Kevin Trenberth, a distinguished senior scientist at the National Center for Atmospheric Research who was one of Christy’s graduate school supervisors.

Looking for signs of global warming? It's all around you , AP, 6/19/18
https://www.mprnews.org/story/2018/06/19/climate-change-signs-all-around

... These days, plants and animals are arriving at Rocky Mountain Biological Lab a week or two earlier than they were 30 years ago. The robins that used to arrive in early April now show up in mid-March.

... Marmots end their winter slumber ever earlier.

Evidence is in the blueberry bushes in Henry David Thoreau's Walden Pond, the dwindling population of polar bears of the Arctic and the dying corals worldwide. Scientists have documented 28,800 cases of plants and animals "responding consistently to temperature changes," a 2008 study in the journal Nature said.

... Starting about 30 years ago, the growing season in general around the Northern Hemisphere "rather abruptly changed to a new normal," with earlier springs and later falls, said Mark Schwartz, a University of Wisconsin-Milwaukee geographer. In the Lower 48 states, 2012 was the earliest growing season on record until it was edged out by 2017, he said.

In the U.S., fall's first frost is happening about nine days on average later since 30 years ago, while the last frost of spring is happening almost four days earlier,

more, much more

... Katharine Hayhoe, a climate scientist at Texas Tech, has heard non-scientists accusing the government or researchers of manipulating temperature data to show warming. There's no cooking the books, she said; nature is broadcasting a clear signal about climate change.