By Abhijit Bhattacharjee  | Earlier this year, I was visiting Bangladesh to review the state of disaster management system in the country. The national government has invested heavily over the years in developing its capacity to deal with various hazards such as floods, cyclones, storm surge, landslides and earthquakes the country is highly exposed to. One morning, as I sat in the restaurant for an early breakfast when it was not too busy, I got talking to Shafiq - one of the waiters who barely looked sixteen, though he claimed to be nineteen. Shafiq had come to Dhaka from southwestern part of the country in early 2013 with his elder sister who had found herself a job at a garment factory. They came to escape poverty and regular floods and cyclones in Patuakhali which was their home. Earlier in 2007, Shafiq's father who was a fisherman and the sole breadwinner of the family was killed during cyclone Sidr which hit the district.

Shafiq told me that back in January 2014 when they came to Dhaka, life was looking good again. Little did he know that two months later, his sister would be one of the 1,140 people killed in the infamous Rana Plaza building collapse.

He had overheard a conversation the previous evening I was having with a climate scientist over dinner and wanted to know if the intensity and frequency of floods in his district will ever come down. He did not like Dhaka and wanted to go back to Patuakhali if the small land his mother had could be made cultivable again. He had heard that the world is getting warmer and that is why during each cyclone and high tide, the sea waves are much higher than what he remembers as a child.

I wish I had an answer for Shafiq.

A few weeks later, back in London I saw a news report that the global concentration of carbon dioxide (CO2) in the atmosphere - the primary driver of climate change - has reached 400 parts per million (ppm) for the first time in recorded history. Scientists tell us that in the last 250 years - since the ushering in of fossil fuel driven industrial revolution - as global CO2 concentration in air increased by 120 ppm, temperature rose by 0.8 degrees celsius (C). That may seem a very small increase to you and me - what is this hand wringing and chest beating about?

To put in perspective, almost half of this increase (0.4 degree C) has taken place in the last three decades alone, fueled by our unquenchable thirst for fossil fuels and insatiable hunger for consumption of anything and everything the fossil-driven economy churns out. Endless consumption, we are told, is good for us, for our economy and for the world.

With a 0.8 degree C increase, we have already been witnessing increasing drought, floods, sea level rise and arctic melt. The Nobel-wining Intergovernmental Panel on Climate Change (IPCC) warns us that unless serious actions are taken, we would see the global temperature rise by over 2 degree C by the end of the century. To ensure that the temperature rise is below 2ºC, the IPCC (2007) calculated that global emissions must peak by 2015 at 400 ppm and drop thereafter (though subsequently this figure was revised to 450 ppm by 2100). The 400ppm peak is certainly not achievable as we are already there, and emissions continue grow at about 2 ppm per year.

The consequences of not staying within this 2 degree threshold will be near-catastrophic for different regions. With increase in greenhouse gas emissions and temperatures, the type, frequency and intensity of extreme weather - such as hurricanes, typhoons, floods, droughts, and storms - are projected to increase; sea level rise up to 5 metres due to retreating Artic and melting of Antarctic ice sheets leading to mass displacement and food shortages are predicted; and thawing of permafrost will lead to further increase in temperature besides dramatic changes in geology and hydrology.

Starting with the Kyoto protocol, countries have made various commitments to reduce emissions based on the principle of common, but differentiated responsibilities. The G8 summit in 2009 set a target of 80% emission cut for industrial economies by 2050. This would require bringing down per capita greenhouse gas emission (CO2 equivalent) to 2 tonnes. Currently (2013), in the EU the average is 10 tonnes per capita, and in the UK and USA, the corresponding figure is 7.2 and 16.4 tonnes per capita respectively.

After an initial rise between 1990 and 2000, emissions declined significantly in the USA and UK in particular. This was mainly due to reductions in emissions from power generation and non-CO2 gases (e.g. methane from waste). The ongoing recession (slow recovery) and some amount of energy efficiency improvement, fuel switching and industrial restructuring and have also contributed to reduction in industry emissions. However, this is still far from the target of 2 tonnes per person.

Hope for realizing substantial changes through current incremental measures remains unrealistic. Scientists have argued that this is unattainable unless radical steps are taken in our production and consumption pattern. Continuing to use the same model of 'Grow-Baby-Grow' model of development, and changing a few light bulbs here, planting a few trees there, and hoping for the best technological fixes to emerge to wash away the 36 billion tonnes of emission our lifestyle spews out every year is a pipe dream.

In the coming decades, the emerging and developing countries which currently account for about a quarter of the global greenhouse gases are going to become big emitters - India, for instance, still has two-thirds of its population with no electricity; or Sub-Saharan Africa has 47% of its population reeling in poverty. The governments in these countries can not be expected to sit back and let generations suffer due to continuing lack of basic necessities, hunger and starvation, just because 30 odd industrialized countries have already heated up the planet so much that we have already crossed the tipping point for global warming.

This is where lifestyle changes comes in, and that's a conversation currently missing from policy discussions and international protocols. If we all continue to hanker after the big mac-burger and the juicy steak flown across continents, the neatly packaged exotic fruit one had never seen before, four cars for each family and the latest model of the smartest phone only to be discarded every six months, we shall all heat up the planet by anything between 1.4° to 6.4° C between 1990 and 2100, according to one UN report. As Mahatma Gandhi had said some eighty years ago, "The world has enough for everyone's needs, but not everyone's greed".

Lifestyle changes can start with simple things. Emissions from agriculture in the UK, for instance, account for around a tenth of all UK greenhouse gas (GHG) emissions. Agriculture emissions reached 54 million tonnes CO2e in 2013 - a little less than 1 tonne contributed by each one of us. Livestock farming produces from 20% to 50% of all man-made greenhouse gas emissions. The carbon footprint of a vegetarian diet is about half that of a meat-lover's diet. Environmental groups have done very detailed analysis of greenhouse gas emissions produced by various types of food and ranked them on the basis of the emissions produced on the farm, in the factory, on the road, in the shop and in our homes.

Meat, cheese and eggs have the highest carbon footprint. Fruits, vegetables, beans and nuts have much lower carbon footprints. If we move towards a mainly vegetarian diet, we can have a large impact on our personal carbon footprint.

So next time, you bite into the juicy piece of lamb shank, think of the gas emitted by your car when you drive 91 miles. That's as much carbon a kilo of lamb on your table is contributing to insidious and irreversible damage to out habitat.

I wish I could tell Shafiq that he probably stands little chance of ensuring that his land escapes the ravages of frequent storm, tidal waves and salinity, and his family may be displaced again. People in Bangladesh have already started experiencing climate change in the form of increased flooding, erratic rainfall, frequent cyclone and drought-like conditions, salinity in water and cropland, sea and river erosion, higher temperature and more frequent high tide. The World Bank estimates that cyclone exposed areas in Bangladesh will increase by 26% and the affected population will grow by about 122% by 2050 (World Bank, 2010).

And this is because the world is failing to make the radical changes that is necessary to avert a catastrophe.

We still have one last change. Later this year, world leaders are meeting in Paris to develop a new global agreement on climate change. Researchers, policy makers, lobbyists and campaigners have been working hard in preparation for the summit to ensure that a good deal is possible. The focus unfortunately still appears to be on how we improve our production methods, how we share our resources, how we continue to 'grow' and how we finance the measures that are agreed. One central question that is not brought into the agenda is: how do we curb the voracious culture of consumerism that is at the root of the plunder, and how do we ensure a more equitable planet?

This question - about endless consumerism and galloping inequity - which has driven all our growth and development, at least in the past three decades, remains central to climate change. And the world has not yet shown enough courage to face it.