A birth rate of 2.159 and falling, is not an exploding population.So far.
But everything so far is water under the bridge. We can't undo what we did, we can only try to not make it any worse. India has a chance to not pollute like we did. But will they take it? Their population is exploding and they want a more affluent lifestyle. In a few years they could be bigger polluters than China, if they don't plan to avoid it.
Their death rate is also going down, but that will level off at some point. India is like nearly every other country: A declining birth rate.
The difference between India and China though is that their demographics won't screw them in the long term, as their population will continuie to grow for longer (and exceed China), but its not set to do so in an "explosive" way.
And:
https://iipsindia.org/the-population-of-india-over-time/The current UN medium projection says that Indian fertility will decline by 1.8 births per woman. As a result, the population of India is expected to reach 1.7 billion by 2060 and decline to 1.5 billion by the end of the 21st century. The lower projection expects fertility to decrease to 1.3 births per woman. As a result, the population will decline to 1.5 billion in 2040 and 900 million by 2100.
https://www.weforum.org/agenda/2020/01/demographics-china-india-diverging/
China’s population has plateaued, and will eventually decline over the remainder of the 21st century. There is plenty of room to grow economically, but the weight of an aging population will create additional social and economic pressures. By 2050, it’s estimated that over one-third of the country will be 60 years or older.
On the other hand, India is following a more traditional demographic path, as long as it is uninterrupted by drastic policy decisions. The country will likely top out at 1.6-1.7 billion people, before it begins to experience the typical demographic transition already experienced by more developed economies in North America, Europe, and Japan.
On the point of emissions, of course they could do more. But getting their population out of poverty must also be a priority. Rich nations must be at the forefront of innovation to help acheiving this.