I think one way to slow the growth is reduce the block reward from 25 coins to just 1 coin per block, there is no way the BTC price will jump 25 fold to compensate as more then half the coins are already mined so there is no shortage of supply, and no reason for that much fiat to enter the market.
According to this formula:
[...]
GlobalEnergyConsumptionForMining ~= (MiningReward + TransactionFees) * bitcoinValueInUSD / EnergyCostInUSDperkWh[/i]
your suggestion might make things 25x better. But there would be a shortage of liquidity on the exchanges driving BTC price. So it's not 25x.
And it only works if people do not pay more transaction fees.
More than half of all the 21million bitcoins that were ever designed to exist are already out there in circulation. Mining new coins is not important to liquidity, we just need to find 144 blocks each day for transactions to ride on, it no longer requires many coins in those blocks as we have enough in circulation, so it might as well just be the one coin. I don't think waiting until 2029 is the answer, the world will be struggling for oil and coal around then unless something else happens to curb world demand.