It would be very interesting to see a breakdown of voting by age. Environmental destruction has a much greater impact to the young.
[edit] downvotes! Why? Is it a crazy idea that young people should have more of a say about their future than old people? Where I live the old generation are fucking over the young generation in a big way.
"Hey, I've seen everything!"
vs
"Hey, that's what I was told on TV!"
Those aren't really comparable. If I have a "no black people" rule or a "no men" rule, some people are permanently excluded and some people are permanently included. Those rules each filter everybody into two permanent classes each that they can never leave.
A "no people under age X" or "no people over age X" rule does not do this. Yes, it does filter everyone in to one of two classes, but any given individual starts in one class and then after a set time switches to the other class.
The problem is bigotry is usually based on an immutable feature. While gender is becoming changeable to certain degrees, age and race are not, one can't de-age a person or change their race on a whim. Additionally, claiming that because someone's older disqualifies them from having a full vote in society opens the floodgate every other manner of depersoning seen in human history over the last 200-500 years.
Realistically, I see no fair way to start disenfranchising people. The best we can hope for is to think about what constitutional controls we have to protect people generally from a tyranny of the majority, and consider if there are additional ones needed to account for demographic majorities. Getting anything passed is another story...
But around a hundred years ago, most democracies decided that every person should have a vote, and that all votes should count the same. Including men who don't own land, women, people of color, poor people, uneducated people and young people.
And I think that, although it might seem worrisome that so many idiots vote against my personal preferences, it's better that way. Because the alternative of having an elite that consider themselves better than the rest always ends in justifying killing all who don't agree or who don't offer enough value.
As far as the actual idea goes, better would be to (1) make it finer gained, and to (2) make it depend on the issue being voted upon.
Maybe something like this (numbers for illustration only--much more thought would need to go into determining the right numbers):
(1) If the life expectancy for an average voter of your age is at least 30 years, your vote weight is 1.00.
(2) If your life expectancy is not at least 30 years, your vote weight decreases as a function of how much under 30 years it is, reaching a minimum of 0.25 at 10 years life expectancy and then staying at 0.25 for the rest of your actual life, unless #3 applies.
(3) If a particular issue will likely have major short term consequences, your vote weight is based on the percentage of that short term that occurs within your life expectancy.
If I'm only expected to live 10 more years and we're voting on something that is going to seriously affect people for much much longer than that, it seems only fair that the people who are going to be more affected should have more say than me. That's what #2 is trying to cover.
#3 is to protect people against front loaded projects. Say the vote is on building something that will take 10 years to build and then have a major impact for the next century, and construction is going to be paid for by a 10 year tax increase. People with 10 year life expectancy would only get a 0.25 vote under #2, but they would be fully hit by the taxes in this case, and see none of the benefit, so they should have more say. #3 in this case would supersede #2 and give them a 1.00 vote.