The China Central Television (CCTV) headquarters (left) is obscured by severe smog in Beijing on Nov 4, 2016. Beijing issued an orange alert for smog on Thursday afternoon, with visibility in some areas dropping to below 100 meters on Friday. [Photo/VCG]

The landmark Paris agreement on climate change finally came into effect on Friday. It is a manifestation not only of the world's awareness of the increasingly devastating impact climate change as a result of human activities is having on the Earth. It is also the demonstration of the resolve of the countries that have ratified it to address the issue with concrete actions.

That is worth celebrating, even though there are about 100 countries that still have to ratify the agreement.

Yet, it is one thing to have such an official global pact. It is another to ensure that countries implement their commitments to the letter.

Will the poor countries get the previously agreed financial and technology support they are supposed to obtain from developed countries in order to reduce greenhouse gas emissions?

Will emerging countries be willing to cut the emissions at the cost of their economic growth?

Will the majority of governments be able to see beyond their own immediate interests for the long-term benefit of limiting the global temperature rise well below 2 C?

For China, this pact is of particular significance, not just because of the role it played in promoting its acceptance, but also because China is the world's most populous nation and also the biggest emitter of the greenhouse gases that are driving global warming.

In China's current development stage, cutting greenhouse gas emissions will quite possibly compromise its economic growth.

However, the smog in China's major cities, including Beijing, is visible evidence of the severity and urgency of the challenge the country faces in cutting its greenhouse gas emissions and the pollutants discharged by enterprises and motor vehicles.

What China has been doing in the recent couple of years and the leadership role it assumed in securing the agreement reached in Paris show that its leaders at the national level have the necessary sense of urgency on this issue.

Yet, this is not the case at the local level, where many officials still pursue the immediate interests of economic growth ignoring the cost to the environment.

So while celebrating the Paris Agreement, we should not become complacent as it requires concrete actions for its effective implementation.

It is better to be late than never when placing enough emphasis on the urgency of dealing with environmental pollution, including the cutting of greenhouse gas emissions. But if we leave it too late, it will be the same as never.