No one is dying from global warming. It's still much cooler than it was in the early Holocene (the Neolithic, or stone age era of humanity) and this was a time of abundance and expansion for farming and agriculture. Even the Sahara was richly farmed at the time. Plants not only thrive under warm temperatures, they also thrive with high levels of CO2. The world is greening:
There is an asymmetric risk, though. Due to feedback loops like methane release, we don't know at what temperature the warming will stop, or how fast it will go. The upper-range estimates are well beyond any temperature from the last 10 million years.
Doesn't it bother you that the temperature rised first, the CO2 levela just followed it. To me if A happened after B, A could not be made responsible for B, i.e. rising CO2 levels for rising temperature levels.
A lot of methane is coming from deep sea hydrothermal sources. You cannot stop that. But methane itself is unstable in the atmosphere and only accounts for less than 2 parts per million.
If the climate were so sensitive to CO2 levels, where we've seen it go from 250 to over 400 ppm...we would see much more dramatic warming than we have. It was not that much cooler 100 years ago. So far, we have yet to have a year significantly warmer than 1998. It's been 22 years and the CO2 has been rising all that time. In spite of billions of people coming out of poverty. Minimal difference in maximum temps. Antarctica had record sea ice extent in 2014. Antarctica has been trending positive for sea ice over the past 30 years: https://earthobservatory.nasa.gov/world-of-change/sea_ice_so...
There's never ever been a geologic extinction event associated with high levels of CO2. In fact quite the opposite: the abundant and biodiverse periods in Earth's history are associated with high CO2.
Plants literally suffocate at 150ppm. We are near historical lows for the planet Earth.
There has been a geological extinction event associated with high levels of atmospheric carbon - it was the biggest one of all time, and it nearly wiped out all life on Earth. Look up the Permian Extinction. (Yes there are multiple theories of cause, but one of which - and perhaps the most likely - is run away global warming.)
First of all, I sourced from NASA. You provided no such sources despite making an extraordinary claim about the Permian extinction. The theories for that event include meteors, volcanoes, microbes, underwater methane release (from geothermal sources) and there is tons and tons of uncertainty about that event. You are oversimplifying by even attempting to attribute blame to CO2, which was already much lower in the Permian than in other eras like the Cambrian and Carboniferous [1], furthermore, temps aren't correlated with CO2 in Pre-Quarternary eras.
Best indications are that a series of super-volcanic events triggered massive drought, which probably led to drying conditions and decreased sunlight for photosynthesis, which triggered massive fires which burnt up tons of oxygen and caused hypoxic conditions for tens of thousands of years. This whole episode is also associated with geomagnetic instability [2]. Now, the two are related, because geomagnetism is caused by movement of the inner and outer core of the Earth. If the earth sees periodic disruptions in the normal movement of the cores, I can easily imagine that to trigger massive volcanic activity.
Now, in that case, a release of CO2 occurred from all the plant matter dying off as a result of drought, fire, flood, and volcanism. The CO2 itself didn't cause the extinction. The volcanism caused the extinction.
Sea level is rising at an unalarming 2-3mm per year. About a foot a century. Believe me, we can adapt to that. Even if you could control the sea level, by the way, due to tectonics, a lot of land is moving at millimeters per year as well. Some landmasses move up, some move down. Change is constant on this planet. Adaptation is the only way.
It actually may drop around Greenland and Antarctica, as well. The reduced mass of ice causes the water level to drop despite the overall sea level rise. This of course means higher rises elsewhere. Surprisingly, this didn't occur to anyone until just a few years ago.
Also, the problem is not that humans in general are incapable to withstand the increased temperatures, but that the extreme changes in climatic patterns and the changes weather patterns will wreak havoc with infrastructure and agriculture. Any species whose lifecycle is tied to the seasons will face decline and possible extinction. With every species removed from the ecosystem, this ecosystem becomes more weak and fragile.
Changes to seasonal weather patterns will make living in some areas untenable, causing local and global migration. And we all know how well established societies are dealing with migration (hit; not good at all).
Oh, I'm a very smart cookie, but surely I'm often wrong, as is everyone. However, if I were to present you with Ph.Ds that agree with me, what would you say? Who is right? Would your instinct be to fall back on consensus...or to fall back on the scientific method?
Or you could also dig into the science yourself, with a skeptical, rational mind and care for the scientific method, and come to your own conclusions. I would recommend learning about everything from thermodynamics to geology to atmospheric science. It's fascinating stuff. We live in an era where it's easy to do that.
Never outsource your thinking to someone else. We live in an age where you can do your own research quite easily.
With any other hard physical science, the math is derivable. I can look at the equations for special relativity, I can read about the aether-related theories that preceded it (which were consensus at the time), I can see where they fell short and how they failed to measure up, I can read about Einstein's thought experiments that the led to the theory, I can read about the fundamental experiments that validated the theory. I can see how it evolved since then and led to developments in quantum physics. I can do all this. And I submit to you that if quantum physics is accessible then certainly climate science and geology are accessible. We have Google Scholar, ScienceDirect, numerous sources for contemporary publications and you can absolutely follow it and you can play a part in it. And then you will know the topic.
I have a PhD and did some research. It would be ridiculous to suggest that people can do research in my field without first investing years of training. I assume it's equally ridiculous to assume that I can do research in climate science without years of training.
I outsource thinking to other people all the time. That's essentially what it means to live in a modern society.
https://www.nasa.gov/feature/goddard/2016/carbon-dioxide-fer...