Unless action is taken to reduce these emissions from farming, production of food will be responsible for the whole of the two per cent increase in global temperatures that scientists believe are allowable before the consequences for the world become devastating.

Ruth Clements, a vet with the Food Animal Initiative, told the British Veterinary Association Congress during the London Vet Show, that as the world’s population grows and the demand for food becomes greater, there is an urgency to change production methods.

She said that the world is going to see an increase in the number of animals on farms and the way they are reared.

“We are dealing with some pretty rapid changes,” Dr Clements said.

“There is an urgency to do things differently.”

Dr Clements showed that between 2000 and 2011 production in beef had increased by 12 per cent globally and fish and chicken production had risen by 81 per cent and 54 per cent.

She showed that the UK was already seeing the effects of climate change and these changes such as flooding were also creating problems in spreading diseases such as liver fluke.

Dr Clements said there is a need to develop systems that are not only good for the animal in welfare terms, but also good for the environment and good for the farmer.

She said production systems need to concentrate on preventative rather than curative and therapeutic management, with nutrition as the key to getting the most out of an animal.

She said that farmers need to be helped to farm more sustainably to get the best from their livestock and at the same time improve the lives of their livestock.

Dr Tara Garnett from the Food Climate Research Network at the University of Oxford told the congress that food production had to be rebalanced to take into account the effects it is having on climate change.

However, she showed that while food and livestock production create greenhouse gas emissions, they also meet a social need - creating employment, feeding people and in some cases using land for livestock that cannot be used for other purposes.

She said that one view would be to produce more intensively and another to switch production from ruminants to monogastrics to reduce emissions.

But she added that intensification of production has implications on the welfare of the animals.

She said there needs to be a rebalancing of the way farms are managed and there also needs to be a new focus on what and how much people consume.

“Diets that have less meat in them have a lower impact on the environment,” said Dr Garnett.

She added that reducing food waste also needs to be taken into account when developing more sustainable food production systems.

“We have to address livestock emissions if we are to keep within the 2°C limit,” said Dr Garnett.

She added that the problem need to be attacked not only from the production side but from “multiple perspectives”.

“We need to shift our consumption patterns,” she said.

Dr Vivienne Nathanson, director of strategic relationships and CSER at the British Medication Association and Health Alliance to Combat Climate Change said there is a relationship between health, wealth and nutrition.

She said the poorest people have the worst health expectation and the richest the best, and the animals of the poorest people also fair less well.

She said food animals do not do well in poor countries because they get poor nutrition.

Dr Nathanson said that with a changing climate there is also a change in the spread of disease and she warned that disease such as malaria could become common in Europe at the climate gets warmer.

She said that one way to do something about climate change is to eat less red meat.

“It is a very inefficient way of producing protein,” she said.

“Eating less luxury food makes the world more equitable” she said.