Green Room: Our writers talk back

Over recent weeks, a number of leading voices in the environmental debate brought you their views on a range of issues in the Green Room.

This week, we have offered the writers an opportunity to respond to your comments.

FIONNUALA WALRAVENS - Ozone protection feels the heat

Read Fionnuala's original article

Read your comments on Fionnuala's article

My original intention was to spark discussion on how environmental treaties need to work in synergy with one another.

However, other than the comments around whether climate change is human induced or not, the majority asked the question: if natural refrigerants are so good then why did we not stick with them in the first place?

it's time to stop coveting convenience and start embracing challenges

It helps to look back at the history of how synthetic refrigerants have developed.

Natural refrigerants were widely used up until the 1950s, but they did have their drawbacks. Ammonia is toxic and hydrocarbons are flammable.

These problems are far from insurmountable as both substances are used widely today; filling a car up with petrol (a hydrocarbon) is not what I'd call a life threatening activity.

But to use these refrigerants safely, it requires a level of engineering maintenance and good product design.

However, in the 1950s along came CFCs, inert gases with good thermodynamic properties. And so the age of synthetic refrigerants was born.

But as CFCs, and more recently HCFCs, are phased-out, we should now be asking how good are HFCs, the current synthetic alternatives?

Well, we know they're bad in terms of their global warming potential but are they as good as refrigerants as their predecessors?

The chemical industry is keen to focus on the energy efficiency argument; they may be shocked to hear that I agree with that approach.

But it's not as black-and-white as saying one is more efficient than the other. In fact, the thermodynamic properties of many HFCs are far worse than the CFCs and HCFCs they replaced.

In countries with high ambient temperatures, hydrocarbons are gaining popularity as a result of their impressive efficiency compared with HFCs.

So yes, phasing out HFCs is a technical dare, but in an era where the threat of rapid global warming is upon us, it's time to stop coveting convenience and start embracing challenges.

Fionnuala Walravens is part of the Environmental Investigation Agency's (EIA) global environment campaign team

COLIN CHARTRES - Growing problems of water scarcity

Read Colin's original article

Read your comments on Colin's article

My contribution to the Green Room triggered many responses that demonstrated that the severity of the water crisis and its link to food production are well understood.

The solution lies not only in developing sustainable population policies, but also in ensuring we invest in water and agricultural R&D

Several responses correctly indicated that population growth is potentially the most serious factor facing water and food production.

Projections indicate that world population will rise by about two-and-a-half-billion people over the next three to four decades.

Many people consider a population of just over six billion to be unsustainable, yet alone nine billion, but it appears unlikely that growth in numbers can be reined in, at least in the short term.

Similarly, increases in dairy and meat consumption have been shown to use more water than diets based on cereals and vegetables, adding further stress to scarce water resources.

Rather than await the gloomy forecasts of doom mentioned by a couple of respondents, scientists continue to look at new ways of producing more food with less water.

This increase in water productivity is achievable and will be based on improving yields through better water management, introduction of better yielding cultivars, pest and disease control and capacity building of farmers.

Improvements will also be made by developing water harvesting and supplementary irrigation schemes to adapt to climate variability and change.

Some of the concepts of organic farming that improve soil organic matter and health, while also sequestering carbon, will also be important but artificial fertilisers will still have a major role in achieving increased crop yields.

At the time of the "Green Revolution", yield increases were running at 3% per year and were generally keeping up with population growth.

Subsequently, focus was diverted away from agriculture into other areas of the economy.

Consequently, investment in the research and development to sustain crop productivity increases became politically less important until the recent food crisis emerged.

As a result of less investment in R&D, productivity increases fell to 1-2% per annum.

The solution lies not only in developing sustainable population policies, but also in ensuring we invest in water and agricultural R&D, infrastructure, improved governance and capacity building.

Dr Colin Chartres is director-general of the Sri Lanka-based International Water Management Institute (IWMI), a not-for-profit research organisation focusing on the sustainable management of water resources for food, livelihoods and the environment

PETER BAKER - Feeling the heat of food security

Read Peter's original article

Read your comments on Peter's article

Well, some respondents had a problem with the T-word - thermodynamics. I agonised about using the term in this context, but now confess to an ulterior motive.

It will soon be 50 years since CP Snow's The Two Cultures. In that historic lecture, he used an appreciation of the T-word as an indicator of which culture you belong to: science or humanities. It became widely debated, but nothing changed.

No one has yet provided a convincing and accessible narrative for how we are to live peacefully in a world of scarce energy and resources

I suggest it's time to revisit Snow's notion and re-examine its relevance in this time of anxiety and doubt.

Your diverse replies reinforce my belief that the broader understanding, synthesis, prediction and application of science are in a mess and many are understandably mistrustful.

But science can at least offer a more coherent vision of how the world functions than, say, a banker, or a trade commissioner.

Some comments referred to the relationship between energy and money: a crucial point that takes us back another 50 years to Frederick Soddy, a brilliant scientist who dared to cross the divide.

"The flow of energy should be the primary concern of economics," he suggested and predicted "a period of reflection in which awkward interviews between civilization and its banker are in prospect".

For his prescience, he was widely derided.

No one has yet provided a convincing and accessible narrative for how we are to live peacefully in a world of scarce energy and resources.

It will have to involve a much improved universal understanding of the physical, chemical and biological limits to which we are all subject.

This is a challenge that science must now urgently face.

Sadly, we live in an age of fundamentalists (religious, market and others), so my viewpoint was a foray into science fundamentalism - that which ultimately supports all our livelihoods and beliefs.

Finally, sincere thanks to you all for so vividly sharing your own thoughts and concerns.

Dr Peter Baker is a commodities development specialist at CABI, a not-for-profit agricultural research organisation

---

The Green Room is a series of opinion articles on environmental issues running weekly on the BBC News website.

If you think there is a topic we should cover or someone we should invite to contribute, tell us using the form below:

Name

Your e-mail address

Town/city and country

Your comment

The BBC may edit your comments and not all emails will be published. Your comments may be published on any BBC media worldwide.

Terms & Conditions