"The only thing we know for certain is that the way we live now is totally unsustainable in the long run"
We "know" this how, exactly? Malthus was saying the same thing in 1798. Paul Ehrlich was saying the same thing in 1968.
They were both dead wrong.
"The battle to feed all of humanity is over. In the 1970's and 1980's hundreds of millions of people will starve to death in spite of any crash programs embarked upon now."
"Hundreds of millions of people will soon perish in smog disasters in New York and Los Angeles...the oceans will die of DDT poisoning by 1979...the U.S. life expectancy will drop to 42 years by 1980 due to cancer epidemics."
What we are doing currently is unsustainable. A lot of our farms are propped up by oil-based fertilizer, which is kind of a bigger problem than our transportation systems being so dependent on oil. We will need to do things differently because oil is a finite resource. (That doesn't mean I agree with doomsayers. Change is a constant. <shrug>)
Malthus was exactly right, but he couldn't anticipate the coming industrial revolution and the explosion of energy availability through fossil fuels. There may be an equivalent revolution looming, but I can see no sign of it. For all purposes, Malthus could be right 200 years late.
Most people seem to stick to "the system has worked for 350 years, so it must be able to go on indefinitely".
Yes, I know of this one and it's precisely the sort of wishful thinking I was mentioning, particularly the sheer disregard of energy related problems (obviously, everything will be easy for ever if finding energy and getting rid of waste heat has some magical solution). You should study some posts from this for a contradictory POV:
"Waste heat" is not a problem for the foreseeable future, by the way.
The mean insolation arriving at the surface of the earth is ~1000 w/m2. The Earth has a surface area of about 5.1×10^8 km^2 or 5.1x10^14 m^2, so the incoming energy from the sun amounts to about 5x10^17 watts.
World electrical power output is only about 2 terawatts = 2x10^12 watts, or 1/250,000 of the heat received from the sun.
Clearly it's going to be a long time before we have to worry about "waste heat" on a global level.
Yes, I've read this several years ago, but you didn't read my links. Because my link use actual arithmetic, while McCarthy only says that those who don't use arithmetic are condemned to fail, then happily proceed with vague numbers and absolutely ZERO actual data.
They use the assumption that population and energy use per capita will continue to grow exponentially, when it's clear that it doesn't. That may be "arithmetic" of a sort, but GIGO, you know.
Essentially every developed country is below replacement level (the United States is an exception, but only due to high immigration).
Find out why that is and then you can discuss the issue without, as McCarthy said, talking nonsense.
I did use actual arithmetic in the waste heat calculation, which I notice that you did not dispute.
It's unsustainable in the sense that behind almost everything we do or eat is a lot of fossil fuel. That's a finite resource which will not always exist.
We "know" this how, exactly? Malthus was saying the same thing in 1798. Paul Ehrlich was saying the same thing in 1968.
They were both dead wrong.
"The battle to feed all of humanity is over. In the 1970's and 1980's hundreds of millions of people will starve to death in spite of any crash programs embarked upon now."
"Hundreds of millions of people will soon perish in smog disasters in New York and Los Angeles...the oceans will die of DDT poisoning by 1979...the U.S. life expectancy will drop to 42 years by 1980 due to cancer epidemics."