How can we tackle environmental concerns?

I would say start by practicing the change you seek. and perhaps seeking a career as a solutions provider of the problem that you are passionate about solving.

It really depends on whether we are discussing real or contrived environmental concerns. In "developed nations" all the low-hanging fruit was picked years ago, and now we tend to propose stricter and stricter rules for smaller and small benefits - if any. The problem of less developed nations dumping plastics into the oceans is relatively simple to cure, through better management of waste. Developed nations' contribution to ocean contamination is vanishingly small.

There is debate over C02 from the burning of fossil fuels. I happen to think it is a two sided coin - the upside of a tiny proportionate increase in atmospheric CO2 has produced a measurable 'greening ' of our planet, as CO2 is the one essential plant food. But I accept for some people it has become (in their imagination) an iconic and dangerous pollutant. Although to assert that a 0.0001 mole fraction increase in CO2 over the past century controls the climate is scientifically problematic. But as an earlier post noted, the answer is obvious - abundant nuclear power. Until we do that, and provide the necessary base-load for an electrified society, we can have as many UN meetings, as many schoolgirl strikes as we like, and the world is still going to burn coal, oil and gas.

In the short term: Nuclear power and solar shades

In the long term: Fusion power and weather control through microwave and laser satellites and near-orbit solar shades.

Make China and India stop polluting the oceans.

On a local or personal level, there are things, but I'm afraid nothing can be done currently on a national level.

Just say pretty soon no more panda. Everybody love pandas

Easy. Quit listening to them