citations please..
My understanding is that without shielding about 5% of the voyagers will get cancer, and that many people consider this a reasonably acceptable risk. Does this make that number substantially worse?
Could you link to an article or study about this? I don't believe that humans will ever reach other stars, but if even Mars is too much, oh well.
Agreed with car - not sure I agree with plane.
Currently we have fission powered submarines and boats. Putting a fission reactor in a plane would be somewhat suicidal, but a fusion reactor would be mostly safe. A large plane is similar in scale to a submarine.
There were recently some rumours about the Russians producing a nuclear powered cruise missile.
I'm not sure a fusion powered plane would be any less crazy. At least with D-T fusion you have a MUCH higher neutron radiation requiring more shielding. OTOH if the plane crashes there's less worry about nuclear waste spreading over the landscape.
That's an enormous "if". Fusion research has been underfunded for decades, we don't even know if we can sustain it, and for a reason I don't get, many ecologists are anti-nuclear. Plus fusion won't solve everything. You won't put a sun core into your car nor your plane, not in the next centuries.
> Even if we don't, the plummetting cost of wind and solar may solve that anyway (by "solve" I mean that as soon as non-fossil fuel power production is cheaper than fossil fuels it becomes economic to remove CO2 from the atmosphere and turn into hydrocarbons).
Oh, you mean the unreliable power sources that sometimes provide electricity, sometimes don't?
> The Earth has also been a lot warmer than it is now
Well yes but 5°C is also the difference between an ice age and a hot age. We're currently in a hot age and the 4°C increase we're heading to are not very engaging. (Remainder, during ice age North America down to NY and Northern Europe down to Paris were covered by enormous glaciers. So what will the climate be in 4°C?). https://xkcd.com/1379/
Also in human history the Earth has never been this hot.
> Too expensive to get to space? Eventually the cost of this will go down to dollars per kilogram.
Ha. To escape Earth gravity you still need to spend 6.2*10^7 J/kg. That's gonna be a long time before we get to 1$/kg given that rocket propulsion is extremely costly (and as far as we know can't rely on atomic energy either). We're still at ~25 000 $/kg. And anyway recent studies show that the human body is unlikely to bear a trip to Mars, let alone the health issues caused by weightless environment.
Edit, source: http://www.pnas.org/content/early/2018/09/26/1807522115. Basically the study suggests heavy ion irradiation is dangerous for the digestive system. The only thing is I'm not sure about the number of mice they used.
> We also seem to have a pretty poor history of predictions when it comes to climate change too.
I mean it's not as if oil companies conducted their own research and reached the very same conclusion in 1977. Oh wait. https://www.scientificamerican.com/article/exxon-knew-about-...
I'm sorry but you're just burying your head in the sand, making the problem someone else's.