To maximise Singapore's contribution to the worldwide effort against climate change, our campaign needs to include a reduction in our consumption of animal-based foods, including fish, eggs and dairy (Climate change campaign on the cards next year; Nov 19).

Fighting climate change by moving towards more plant-based diets is not a new idea.

In 2006, a United Nations report, Livestock's Long Shadow, noted that production of animal-based foods accounted for a greater percentage of human-produced greenhouse gases than all our cars, planes and other forms of transport.

There are two main reasons for this.

First, animal-based foods are inefficient.

Animals do not produce 1kg of meat, eggs or milk for each kilogram of food they eat. We have to feed many kilograms of plants to the animals to produce just 1kg of animal-based foods.

To grow this plant food, we have to cut down trees, which could have otherwise soaked up carbon dioxide, the most common greenhouse gas.

The second reason why our climate change campaign should include the reduction of animal-based foods lies in the fact that the digestion and excretion processes of cows, pigs, chickens, fish and other animals produce nitrous oxide and methane - greenhouse gases even more potent than carbon dioxide.

Making diet a cornerstone of the fight against climate change has at least three advantages.

One, when it comes to diet and climate change, every little bit helps. For example, it is a step in the right direction if we switch from ordering a meal of two meats and one vegetable, to a meal of two vegetables and one meat.

Two, all of us eat multiple times each day. Thus, we can do our little bit against climate change at every meal.

Three, because research suggests that increased consumption of plant-based foods helps prevent diseases such as diabetes and heart disease, we will be protecting not only the environment but also our health.

George Jacobs (Dr)