The U.S. government released a major report last week about a vast and growing threat to the country's economy, ecology and human health.

The public might expect something like that to be a high priority for public servants, but this report had an oddly subtle rollout. Not only was it released on a Friday — generally the hardest day of the week for breaking news to gain traction — but it came out on Black Friday, one of the more distracting Fridays of the year.

The report is a sweeping view of climate change in the U.S., drawing on the latest science to explain what's already happening, what could happen next and what can still be done. Known as the National Climate Assessment (NCA), it's issued by a group of 13 federal agencies that are legally required to do so every four years. This year's release had been slated for December, during a big scientific event in Washington, so the abrupt shift to Black Friday caught many by surprise — including scientists who worked on the report. Given the Trump administration's unabashed disdain for climate science, this was widely seen as an attempt to "bury" the report.

The White House has done little to dispel that idea, telling the BBC the report is flawed because it's "largely based on the most extreme scenario." (That critique is "demonstrably false," according climate scientist and NCA contributor Katharine Hayhoe, who noted on Twitter that "I wrote the climate scenarios chapter myself so I can confirm it considers ALL scenarios.") On Monday, the president said "I don't believe it" when asked about the NCA, adding that he had read some of it.

The agencies that produced the report haven't shed much light on the scheduling change. "It's out earlier than expected," a spokesperson for the National Oceanic and Atmospheric Administration (NOAA) said during a Friday press conference, according to The Atlantic. That was followed by a reassurance the report itself "has not been altered or revised in any way to reflect political considerations."

And so, timing aside, this report offers an evidence-based overview of historic changes unfolding across the country. The previous NCA came out in 2014, and the new edition has two parts: one released in 2017, followed by this second volume a year later. With the link between climate change and human activities already well-established, the new volume shifts the focus from causes to effects.

It isn't a light read at roughly 1,600 pages, but as Hayhoe tells The Atlantic, "This isn't information that's only for the federal government. This is information that every city needs, every state needs, increasingly every business needs, and every homeowner needs. This is information that every human needs."

Here are a few important takeaways from the report:

Climate change is already happening.

wildfires and climate change graph Analyses suggest the area burned by wildfire across the Western U.S. from 1984 to 2015 was twice what would have burned without climate change, according to the National Climate Assessment. (Photo: U.S. Global Change Research Program)

"The impacts and costs of climate change are already being felt in the United States, and changes in the likelihood or severity of some recent extreme weather events can now be attributed with increasingly higher confidence to human-caused warming," the report states. Despite the common mischaracterization of climate change as a future problem, its effects are wreaking havoc across the country right now.

Since the start of the 20th century, annual average temperatures have increased by 1.8 degrees Fahrenheit (1 degree Celsius) across the contiguous U.S., the NCA points out. Certain extreme weather events have become more common, intense or longer-lasting, from heat waves to heavy rainfall. Drought and heat have helped fuel more large wildfires in Western states, while sea levels along U.S. coastlines have already risen by about 9 inches (23 centimeters) since the early 1900s.

"Climate change is transforming where and how we live and presents growing challenges to human health and quality of life, the economy, and the natural systems that support us," the report's authors write. Climates do change naturally over time, but the report makes clear that "Earth's climate is now changing faster than at any point in the history of modern civilization, primarily as a result of human activities."

It offers a detailed look at how those changes are already affecting American ecosystems, economies and public health, both at a national level and with specific sections for 10 regions across the country. The risks vary widely by region, the report notes, from historic droughts that fuel wildfires and wither crops to rising seas and stronger storms that increasingly threaten coastal communities.

Climate change is a public health crisis.

projected mortality rates due to extreme temperatures in the U.S. The maps above show estimated changes in annual net mortality due to extreme temperatures in 49 U.S. cities for 2080-2099. These changes are projected to cause anywhere from 3,900 to 9,300 additional deaths per year. (Image: USGCRP)

The pace of modern climate change is upending many U.S. ecosystems, altering them too quickly for some creatures to relocate or adjust the timing of their migrations. And while civilization may seem to insulate us from this kind of upheaval, that's an illusion. Not only are we vulnerable to the same forces that now threaten wildlife, but we also rely on those ecosystems more than many of us realize.

There are direct dangers from surging temperatures, which promote heat waves that can be especially dangerous in urban areas with sparse forest cover. The U.S. heat-wave season has already expanded by more than 40 days, and as cold waves dwindle while heat waves intensify, "increases in heat-related deaths are expected to outpace reductions in cold-related deaths" in most regions, according to the report.

Warmer climates also pose lots of indirect dangers, altering weather patterns in ways that worsen droughts and fires in some places while boosting storms and flooding in others. Precipitation is rising across the Northern Great Plains, Midwest and Northeast, for example, and falling in the Southwest. By the latter decades of this century, precipitation spikes of up to 20 percent are projected for the north-central U.S. in winter and spring — and more than 30 percent in Alaska — while spring precipitation is projected to fall by 20 percent or more in the Southwest.

More heat and rainfall tend to benefit pests, too, from moths and beetles that raid crops to mosquitoes and ticks that spread disease. Mosquito species that can spread Zika and West Nile viruses are enjoying a range expansion, for example, as are ticks that spread Lyme disease. And thanks to warmer winters plus more carbon dioxide in the air, pollen allergy seasons are growing longer and more severe.

And then there's air pollution, which already plagues more than 95 percent of the human population and causes millions of premature deaths every year. This problem doesn't depend on climate change, of course, but hot, sunny days can make ground-level ozone worse, the NCA notes, while more big wildfires produce more particulate matter — even in cities far from the fire itself — and stagnant weather conditions can boost concentrations of both. "Short- and long-term exposure to these pollutants results in adverse respiratory and cardiovascular effects," the report's authors write, leading to more hospital visits and premature deaths.

Climate change is an economic crisis.

frequency and cost of water-related disasters in the U.S., 1980-2015 These graphs show (a) billion-dollar water disasters (tropical cyclones, flooding and droughts combined) each year in the U.S., and (b) the associated costs (in 2017 dollars, adjusted for inflation). (Image: USGCRP)

On top of the risks to human health, climate change is also unsustainably expensive. As extreme heat becomes more common, for example, the ability for people to work outside in the U.S. is projected to fall by 2 billion hours per year, according to the NCA, costing the U.S. economy roughly $160 billion per year by the late 21st century.

Along U.S. coastlines, about $1 trillion in public infrastructure and private property is threatened by rising sea levels, larger storm surges and tidal flooding, not to mention the heavy rainfall dumped by some recent tropical cyclones like Hurricane Harvey in 2017. Even without bigger hurricanes and other storms, coastal erosion alone accounts for about $500 million in damages per year, for which the U.S. spends an average of $150 million per year on erosion-control measures. The costs of wildfires are rising, too, both in terms of property damage and firefighting efforts. The U.S. typically spends about $1 billion annually to fight wildfires, but spent nearly $3 billion in 2017 due to extreme drought conditions in some regions.

Shifting weather patterns can also endanger agricultural crops, both with longer droughts and stronger storms, threatening economic stability as well as food security. Livestock is at risk too, with dairy cows especially sensitive to heat stress because it weakens their appetite, according to the NCA. "In 2010, heat stress was estimated to have lowered annual U.S. dairy production by $1.2 billion," the report states, adding that dairy production will likely suffer the largest declines across the Southern Great Plains and the Southeast due to increasing heat stress.

There's no time like the present.

coal-fired power plant Sunrise illuminates a coal-fired power plant near Bismarck, North Dakota. (Photo: Andrew Burton/Getty Images)

Some amount of climate change is already locked in due to past emissions, so adaptation is a key part of any good coping strategy. Adaptation measures have increased since the last NCA, according to the new report, but they haven't kept pace with the worsening effects of climate change so far.

That leaves the obvious but daunting challenge of curbing the greenhouse gas emissions that are fueling modern climate change. Although the Trump administration has infamously pledged to withdraw the U.S. from the Paris Agreement, the NCA notes that some state and local governments, along with many private-sector entities, have announced plans to reduce their emissions in hopes of minimizing the impact of this move. U.S. emissions have already dipped slightly in recent years, thanks partly to market forces like the decline of coal-fired electricity and the growth of renewable energy, but they will need to drop a lot more if we're going to avoid the worst-case scenarios for climate change.

The NCA stops short of making policy recommendations, but as the World Resources Institute argues in a blog post about the report, "the policy implications should be perfectly clear." Aside from adapting to the warming we've already caused, the key to saving ourselves from climate disasters largely depends on reining in greenhouse gas (GHG) emissions. And while the U.S. can't stop climate change on its own, that's the point of international accords like the Paris Agreement, which has been ratified by 184 countries that account for 88 percent of global GHG emissions.

The U.S. may end up regaining its climate leadership role in the near future, but even in the meantime, there are rays of hope for the country's ability to reduce emissions and brace itself for the turmoil ahead. And this report embodies one of the simplest but most important things that both policymakers and voters can do: Don't ignore or forget climate change, even when we're surrounded by distractions.

4 things you should know about the Black Friday climate report
A new U.S. report on climate change offers 'information that every human needs.'