Blog Entry No. 1 - Summary of Speech Given by Dr. Liong Shie Yui

Dr. Liong talks about climate change and ways to predict these changes through studying climate models.

In the first part of the presentation, he started off by defining climate and showing a trend of temperature throughout several months. He also stressed that climate change is not the same as weather change which is highly predictable. Basically, climate is an average calculation of rainfall and temperature over a long period of time. Extensive research has shown that the temperature of the Earth has shown a drastic increase in the last 100 years especially most significant at both the North and South Poles. This is invariably caused by the increase in greenhouse gas emissions due to human activity.

Greenhouse gases prevent the reradiated heat from the sun from escaping into space. This is called the greenhouse effect. Dr. Liong used an analogy of an umbrella referring to the stratosphere, where this “big umbrella” traps the greenhouse gases. Although this is a good process which keeps the Earth warm, too much of these gases are causing global warming. The largest greenhouse gas emission is no doubt carbon dioxide (CO2) which is produced when we burn fossil fuels for energy and through deforestation (i.e. forest fires). Other gases like methane, nitrous oxide and fluorinated gases although are emitted in less amounts, are much more potent than CO2 at causing greenhouse effects. It is thus important that we not overlook these gases when analysing the factors that causes climate change. There is no doubt that the global warming is caused by human activity and not natural forces as there has been no record of drastic temperature increase since the start of Earth’s history till the 1900s which is when humans began the Industrial Revolution.

In the second part of Dr. Liong’s presentation, he introduced to us the Intergovernmental Panel on Climate Change (IPCC) and its efforts to estimate the changes in the climate and thus formulate ways to pre-empt or minimise damages. In his presentation, Dr. Liong showed us a picture from the 2007 IPCC report, AR4, with two different emission scenarios of how the future climate would look like with variable energy sources. Scenario B1 which was the most ideal scenario was emphasized by him to be unlikely. The report also shows that rise in sea levels and temperatures of the Earth are expected even after the stabilization of CO2 levels. To estimate changes in the climate more specifically to each region, the IPCC uses Global Climate Models (GCMs) which divides the Earth up into square grids. However, the GCMs are just a prediction and models of the same region can differ. In the case where contrasting climate models are presented, the majority result is deemed more accurate.

For small countries like Singapore, a GCM model would be too big for it to make sense of the results. Thus Regional Climate Models (RCMs) are used instead, which divides the bigger grid squares of the GCM into smaller ones. This downscaling of climatic values allows more specific climate changes to the area with regards to the terrain and proximity to coastal areas. It is then clearer for the analyzers to see which parts of the country would have more changes in temperature or precipitation. However it is also not viable to only look at the area in the RCM to estimate the climate change as many factors influencing the climate of the area is of another region. An example given by Dr. Liong is the wind that blows from Vietnam that results in increase in sea level and precipitation in Singapore. Thus we must also include the regional climate factors in our analysis of the climate in the particular area. Dr. Liong also mentions of how the climate models are difficult to analyze and make sense of. It is thus necessary to look at the bigger picture of the climate model, whether it has a net increase or decrease in temperature or the intensity of the net increase in temperature.

In conclusion, although the future prospects of the climate is not ideal, the GCM and RCM can be used by the country for hydrological impact studies which is then used to formulate ways to mitigate climate change. Climate models are thus very important for the government with regards to formulating policies regarding the environment and land use planning.