The earth and the climate don't care who pollutes how much. The total amount of pollution matters and there shouldn't be a privileged few consuming magnitudes higher than the rest. Plain and simple.
I suspect we'll get there.
What I'm less certain of is what that standard of living will be.
Sorry, I'm not parsing that. Are you missing a negative somewhere?
My intended meaning: a greater level of allocation equity may be achieved. If we're lucky, it's going to be at a relatively high level (I'd be happy with a late 19th / early 20th century industrialized world equivalent). If we're not, it will be at subsistence agricultural levels -- somewhere between late bronze and early iron ages.
Modern industrialized civilization is a tremendous heat engine, and without high-quality fuel inputs, it will cease to function. That will tend to decrease global wealth and population drastically.
As to the statement: life ain't fair.
There's a question of whether it's better to let some survive and/or thrive, and others not. It goes back a long ways. One of the more recent debates emerged when Garrett Hardin published his "Lifeboat Ethics" essay in 1974, which prompted fierce debate for several decades.
There are two other possibilities you don't consider:
1. India could prevail in negotiating for carbon emission reductions elsewhere (the US, EU, Japan). Technology transfers greatly increasing India's GDP/bbl wouldn't hurt either -- it's presently around $400/bbl, the US sees $1000/bbl, most of Europe is in the $1500-$3000/bbl range.
2. Stunning advances in renewable, sustainable, and/or low-carbon energy technologies could allow for growth in India's standard of living without additional carbon emissions. I put the likelihood of this as low.
Long run: there's a balance of population and per-capita resource consumption. The total sustainable rate is fixed. The question is: do you wish for a future with a very high population, or a for one with a high per-capita standard of living? They're at odds.