One reason is that it is quite costly to do it in sufficient scales. The other reason is probably people expect that the oceans would be able to cope with the changes.

I do support the view of Zhonghe Pang. In addition, it appears to me that people are reluctant to do any thing regarding global issue like this due to difficulties in various aspects, Instead, people expect that it is better to get involved in making proper arrangements to develop the method to combat any forthcoming undesirable consequences. As a result people are probably more interested in disaster management activities by their own way for protection than thinking of getting rid of global warming. At this, my opinion is that human race, most probably will not be destroyed by natural disaster suddenly, they will have to cope with the environmental changes by reversing the evolutionary stages as they have appeared in this Earth in ancient times to complete the cycle and finally to be extinct. Moreover, the rich people might be thinking to take shelter in another planet.

I think the current sentiment is the likely reason. It is simply too expensive with our current technology to make a substantial change in CO2-levels. There are of course ways of trying to mitigate the levels (and not the effects) by increasing photosynthesising vegetation. Planting more trees is one of the most popular and publicity friendly ways of currently doing it. In the same line of thinking there are other ways, kelp-forests, urban greening etc. It's also possible to capture atmospheric CO2 and create materials out of them, but the same applies here, it's simply too expensive on a large scale.

There are therefore two ways to continue with this line of thinking: either our technology has to improve to compensate for it being expensive OR energy has to get cheaper. I think both are likely to improve with time, with sustainable fusion reactors being the likely turning point in vacuuming the atmosphere for CO2.

I've spent 35 years teaching students about the geological history of Earth's climate, in both mainstream public colleges and universities (25 years) and a major Tribal college (10 years), and I can point to 2 major causes of climate change apathy: 1) science literacy in the US is extremely low and declining, and consequently the general public doesn't really understand the impending peril or even pay attention, and 2) political leadership in the US doesn't prioritize science/climate change over short-term political goals. I strongly suspect that the US is not alone in this situation.

I am just studying Environmental management so my answer here will not be as academic as others but...

Ignoring climate change are also down to capitalism. I see cranes everywhere building lots of apartment blocks on acres of land which could be home to trees and other green plants.

They get away with this by putting a small piece of grass in the middle and giving the council some money for affordable homes elsewhere.

Capitalists need to understand that, no matter how much you have, you can't breathe money!!

Since the major contributors to the CO2 emission do not take practical measures, other countries will have no incentive for such practices.

One is cost, the other is Industrialists control the global politics