Saturday marks two years since President Trump announced he would pull the U.S. out of the Paris Climate Agreement, and the scientific case for acting to slash planet-warming emissions of greenhouse gases has only grown stronger since then.

The big picture: Climate science is now more clear than ever about the damage climate change is already causing, whether it be via sea level rise, heat waves or epic deluges. Scientists tell Axios they now have:

• More confidence in the observed amounts of global warming, showing the planet has been heating up faster than previously thought.
• More confidence in tying various (though not all) types of extreme weather events to climate change.
• Clear evidence that virtually all of the observed warming since 1950 is due to human activities.
• Robust data showing that limiting global warming to the Paris targets of 1.5°C or 2°C would have significant, tangible benefits.

In addition, estimates of ocean heat warming have been revised upward in recent years, according to Zeke Hausfather of Berkeley Earth. At least 90% of added heat is going into our oceans.

“Over the past two years we’ve learned that key impacts of climate change, like the melting of ice, the rise in sea level and the increase in devastating weather extremes, are playing out faster than our models projected just a few years ago," Michael Mann of Penn State University tells Axios.

Between the lines: A study published last week projected that unchecked growth in greenhouse gas emissions could cause global sea levels to rise by an average of 3.6 feet by 2100.

• This compares to just 2.3 feet if warming is limited to 2°C, or 3.6°F, above preindustrial levels, co-author Robert Kopp tells Axios.

The difference between business as usual and meeting the Paris temperature target by 2100 is especially clear when modeling the worst-case scenarios.

• For example, Kopp says that there would be a 1-in-20 chance of 7.8 feet of sea level rise under unchecked emissions. Such rapid and extensive sea level rise could imperil coastal megacities worldwide within the next few decades.
• This would drop, though, to a 1-in-20 chance of 4.1 feet of sea level rise in a 2°C world. 

Studies also show that limiting the amount of warming decreases the likelihood that we'll trigger climate change tipping points, such as the loss of the West Antarctic ice sheet.

But, but, but: Emissions are heading in the wrong direction, having hit a record high in 2018.

"As long as emissions are unconstrained, our situation is getting worse. At this point, we're rapidly running out of runway. Rapid mitigation will be politically challenging, as will be the required levels of adaptation. If we do neither of those, then we'll be left to suffer through the unabated impacts of climate change. It will not be pretty."

Piece by piece, scientists are starting to solve the puzzle of the ancient, evolutionary relationship between humans and their microbiomes, Axios' Eileen Drage O'Reilly writes.

Why it matters: The genetic world that stems from bacteria, viruses, fungi and other microbes inside or on the human body is suspected of playing a role in many aspects of human life, ranging from beneficial immune support to debilitating diseases.

Background: Each person has a unique microbiome world in and on different parts of the body that fluctuates depending on factors like age, environmental stressors, infections and seasonal nutrient availability.

What's new: In the second part of a more than decade-long project to decode the genetic influence from these mysteriously important bugs, the Integrative Human Microbiome Project published 3 studies Wednesday in Nature and Nature Medicine that look at how changes in the microbiome could be related to inflammatory bowel disease, prediabetes and preterm births.

Details: The study on prediabetes found that people who were at risk of developing diabetes tended to have different microbes. And people whose cells are resistant to insulin (as are most prediabetics) showed different changes in their microbiome in their response to viral infections or other infections.

• "[T]his study offers some new leads to define the biological underpinnings of T2D [Type 2 Diabetes] in its earliest stages. These insights potentially point to high value targets for slowing or perhaps stopping the systemic changes that drive the transition from prediabetes to T2D," National Institutes of Health director Francis Collins writes in his blog.

Go deeper: Read more of Eileen's story.

A group of scientists are trying to mimic the physics of a black hole on a tiny scale to figure out how these massive and extreme objects work in deep space, Axios' Miriam Kramer reports.

• A new study in the journal Nature details the creation and testing of this laboratory-based black hole that uses sound waves sent through a quantum substance known as Bose-Einstein condensate to test the underlying physics of these objects.

The big question: Stephen Hawking theorized that if two quantum particles appeared near a black hole, one could fall into its event horizon, and the other could escape, creating what’s now known as Hawking radiation.

• Researchers may never be able to test this theory on a real black hole in space, so creating a laboratory analogue is as close as we can get.

What they found: The analogue black hole effectively used sound waves instead of light to mimic black hole physics.

• One-half of the Bose-Einstein condensate fluid flowed at supersonic speeds, with the other at subsonic — the boundary between the two effectively acts as the analogue’s event horizon.
• When the scientists sent sound waves through the fluid, they found that some pairs of waves would appear near the event horizon, with one falling in and the other escaping, much like what’s expected to happen with Hawking radiation at a black hole.
• The researchers were also able to measure the temperature of the radiation in the experiment for the first time, which matches what Hawking predicted.

But, but, but: This new study isn’t conclusive proof that Hawking radiation is happening on a large scale in the universe, but it could help refine these analogue experiments more in the future.

The bottom line: “One could also argue that it is already sufficiently exciting to discover that something as exotic as Hawking radiation predicted for astrophysical black holes can also be found in other completely unrelated systems,” Daniele Faccio, a black hole scientist at the University of Glasgow, told Axios via email.

The U.S. has been hammered by an onslaught of severe weather, as a persistent weather pattern set up a clash of seasons across the central U.S.

By the numbers: Meteorologist Sam Lillo broke down some of the tornado statistics on Twitter. During the past 30 days, the U.S. has seen:

• 584 tornado reports.
• 13 straight days with 8 or more tornado reports.
• 10 straight days with 16 or more tornado reports.
• Only 3 days without tornado reports.
• 185 severe weather watches issued by the Storm Prediction Center.

Between the lines: Epic flooding has also been affecting the Upper Midwest, Plains, central U.S. and Mississippi River Valley this spring, with many locations seeing their highest water levels on record.

• Parts of Oklahoma have picked up more than 400% of their typical May rainfall.
• As of May 29, the Mississippi River in the St. Louis area has been at or above flood levels for over 70 days, according to the National Weather Service.

Context: While the heavy rains are consistent with studies showing an increase in heavy precipitation events and stalled, highly amplified weather patterns due to climate change, trends are tougher to discern with tornadoes.

Studies suggest that environments supporting severe weather will increase but become more variable in coming years, leading to potentially bigger tornado outbreaks that are fewer in number. They also project an eastward shift in "Tornado Alley" as the climate warms and storm environment changes.

Report points to problems with NASA's Europa plans (Miriam Kramer)

Historic flooding swamps Oklahoma, Arkansas as storms prove relentless

SpaceX's Starlink has a new foe: Astronomers (Miriam Kramer)

The life and death of a great telescope (Miriam Kramer)

Measles cases break 25-year record in the U.S. (Eileen Drage O'Reilly)

Anthropocene now: influential panel votes to recognize Earth’s new epoch (Meera Subramanian, Nature News)

Thousands of seabirds starved to death in the Bering Sea — and scientists see evidence of climate change (Brady Dennis, Washington Post)

‘What’s my real identity?’: As DNA ancestry sites gather more data, the answer for consumers often changes (Damian Garde, Stat News)

The US Government Botched Its Investigation Into The Mysterious “Sonic Attack” In Cuba, Emails Reveal (Dan Vergano, BuzzFeed News)

One of the things that makes Mars loom large in our imaginations is just how Earth-like the planet is. For example, Mars has clouds that at least look like those seen on Earth.

Details: According to NASA, the clouds can be found about 19 miles high and are likely composed of water ice, making them similar in concept at least to cirrus clouds here on Earth, though those are typically found at about 6 miles up.

Also, Earth's atmosphere is far more hospitable compared to Mars.

The air on Mars is far thinner than Earth's, containing mere traces of oxygen and an abundance of carbon dioxide.

The big picture: NASA researchers are trying to gain new insights into Mars' clouds by coordinating pictures between the navigation cameras on Curiosity and NASA's InSight lander, which is about 370 miles away on the red planet's surface. "Capturing the same clouds from two vantage points can help scientists calculate their altitude," NASA said.