The following points could be part of the answer to explain why burning fossil fuel contribute to GHG taken into consideration that CO2 is the most risky gas out of the six main GHGs:

- The 38% increase (in 2009) in atmospheric CO2 observed since pre-industrial times cannot be explained by natural causes.

- When we add the observed CO2 increase in the atmosphere to the observed increase in the oceans, the sum is approximately equal to all of the coal, oil, and natural gas burned since the 19th century.

-Furthermore, the observed progressive depletion in carbon-13 shows that the source of the CO2 is either fossil fuels or deforestation because both produce CO2depleted in carbon-13.

The IPCC reports are the single best source of peer-reviewed and curated information, even in the opinion of leading climate change skeptics (see Cool It by Bjorne Lomborg, for example), and the summary for policy makers provides a good overview. Serious consideration of this topic would inevitably rely heavily on these reports. The technical information is produced by working group 1 (WG1). These are published about every 7 years, and an advanced copy of the most recent one, referred to as Assessment Report 6 or AR6, is available on the web (https://www.ipcc.ch/report/ar6/wg1/) and was released in a preliminary form in July of 2021. Early versions of the reports made quite modest statements about the reality of climate change and its origins. AR5 and especially AR6 provide compelling evidence that climate change is real and is driving several globally significant changes in our ecosystem and that CO2 and CH4 emissions associated with human activity are the overwhelming cause of the change.

These reports contain curated summaries of primarily peer-reviewed literature but no original research, so they are a little dated even when they first appear. However, for your purposes they should provide reliable and topical information. You should know that much of the popular literature (news reports) and political commentary on this topic is not supported by the data in these reports. Read the reports and refer people to them for technically sound conclusions. AR6 indicates that climate change requires urgent and global action. There are three working groups. Only the first one, which focuses on the scientific basis of climate change, has provided their report for AR6. The other two, one that discusses vulnerabilities and one that discusses mitigation options, will not be published until 2022.

Hello Tan Lii Wen

CO2 is one of the biggest contributor of greenhouse gas (GHG) in the world. Singapore's NEA report shows that CO2 is number 1 in the country as GHG. And in Singapore's NCCS report, the country's CO2 primary source come from power generation sector (nearly 40%). Power plants in Singapore use mainly oil or gas, and they are fossil fuels. I hope this helps as a starting point. All the best.