They say that a change is as good as a rest, and many people who've made sharp turns in their working lives report the invigorating effect of undertaking novel activities in fresh surroundings.

In the current climate, though, for those experiencing, or threatened with, redundancy a period of enforced rest might be the only option before the economy picks up. Some will use that time to acquire new skills to enhance their employability and reduce their vulnerability to redundancy in the future. For many in that category, a move towards working in the environmental sector, or adding some environmental credentials to their existing CV, might be the way back into employment and, more important, job security.

The fact that many people are switching roles into this broad area of work is reflected in the continued growth in membership of the Institute of Environmental Management and Assessment (IEMA), the leading umbrella organisation which promotes best practice in the sector, and whose members work within it.

Download the new Independent Premium app Sharing the full story, not just the headlines

"Membership is rising all the time," says IEMA's acting chief executive, Martin Baxter. "It's gone up 5 per cent since the beginning of this year and now stands at nearly 14,700." But the attractiveness of jobs in "green" roles means there's plenty of competition for vacancies, so there's a word of caution from IEMA's membership director, Claire Lea.

"Environment is a popular area, it is high profile in the press and high on the Government's agenda with regard to skills for a low-carbon economy. So it's important for anyone considering a career change to think about what particular job roles or areas interest them," she says.

"The range of environment jobs is really wide, and depending on the area you choose, the training and development needed to secure a position will vary."

An exhaustive list of roles in the green sector would take pages to complete, and be out of date almost immediately, since the sector is expanding all the time, but there are two broad categories. The first includes the in-house environmental co-ordinators or managers working within organisations whose main function is something else, possibly banking, selling computers or making car components. A large multinational body may have a mini hierarchy of 30 people in these roles, while a smaller organisation will have just one.

Then there is the growing number of environmental consultancies whose staff give advice to organisations on a range of environmental issues, such as energy efficiency, waste management, noise and air pollution, and sustainable use of resources. A large proportion of these consultancies are sole operators, often people who used to work in large organisations and have now set up on their own. Some are highly specific, with activities concentrating on a narrow area.

An example in this last category is Betts Ecology, a Worcestershire-based firm that specialises in the assessment of proposed development sites with regard to any protected species, including animals, birds, insects or plants. Specialist ecologists from Betts visit sites, looking for bats, newts, otters, owls and countless more species, and ensure their environment is protected during and after any building work.

The contrast between a job involving night work on a bat survey and one monitoring the gas coming out of a factory chimney underlines the importance of doing research before deciding to target the environmental sector in a search for new employment.

Lea's advice is to talk to people who have done or are doing the types of roles that interest you, to find out what they actually do when they're at work. Many firms will be happy to allow people in to shadow someone for a day, which is as good a way as any of judging whether or not you are likely to be comfortable in that working environment.

Many such career changers are helped by Allen and York, one of the biggest specialists in recruitment in the environment sector, with 55 consultants devoted to such work. The firm's business manager, Joe Heppenstall, who used to be an environmental surveyor, says some people manage to move across to the sector with little or no extra training.

"The biggest area here is people with generic project management skills, picked up in another industry, such as construction, for example," he says. Or sometimes experience of a specific business role proves easily transferable. Allen and York managed a move recently for a telecommunications firm employee, whose role was buying land for new masts. He moved to a role buying land to site wind turbines.

Other career movers will need only a small amount of retraining to operate in an environmental field. For example, people who have generic skills at assessment and report writing. Heppenstall knows of environmental consultancies that take such people on and give them training to become environmental assessors, visiting offices, factories and other workplaces.

"There's evidence showing that people in this category are taking a pay cut to get into the sector, but also that they are working their way up pretty quickly, which shows that in the sector the cream will rise to the top," he says.

Among those taking a pay cut to make this sort of a career move are those who have been forced into the position by redundancy, many of whom are given a pot of training money by the employer they're leaving as a means of trying to help them find a new career. Recruitment agencies are often called in by the HR departments of firms cutting jobs, asking for advice to help staff spend their training money on acquiring skills needed in the environmental sector.

Such money can help to pay for a relevant specialist Masters degree or, if the candidate is starting from scratch, towards a basic qualification covering essential starter knowledge.

Here the IEMA Associate Certificate course, which includes the core knowledge that people need to be active in any environmental role, has gained widespread recognition across the industry. The course, which consists of 10 days of study, is run by training organisations across the country, approved by IEMA, with fees ranging from £1,500 to £2,000.

IEMA's website ( www.iema.net) carries adverts for many of these courses, and also has details of its own workshops providing more in-depth training in numerous specialist areas.

In that regard, Chris Kiernan, head of the environmental section of Cobalt Recruitment, endorses the importance for aspiring career changers of beefing up CVs to demonstrate specialist knowledge. He suggests the BRE (formerly the Building Research Establishment) as an example of a source of information about relevant qualifications for those targeting jobs with a construction element.

But he also stresses the value of highlighting generic business and employment skills picked up in earlier, non-environmental roles.

"While you may not tick all the boxes in a purely technical sense, do think about core transferable skills which the prospective employer would benefit from: skills such as project management, current commercial and financial responsibility, team-working, presentation, communication and IT," he explains. "These all feature heavily in an employer's decision-mak ing process."

'I've booked myself on courses to increase my knowledge'

Natalie Loben is operations director for Betts Ecology, which specialises in surveying sites for the presence of protected species. She joined the firm in 2007 after working as an IT manager for a big car franchise.

"We provide builders and landowners with a solution to ecological requirements on their sites, relating to protected species.

To this end, we do site surveys and get involved in planning applications and sometimes litigation, which we are doing more and more of, because people are finding it difficult to navigate their way through Euro legislation. My role is to control the ecologists who go out on site, so I'm learning an awful lot day by day about ecology. For example, I now know that the great crested newt season (when they can be seen and surveyed) is from mid-March to mid-June, and the bat season is from May to September.

I've booked myself on courses to increase my knowledge; I'm going on one soon, organised by Ciria (Construction Industry Research and Information Association) on wildlife on building sites.

The biggest difference in this job is that the ecologists who I'm working with here are out on site most of the time, so they have to manage themselves.

I can't control them like I could the machines and the people in my previous job, and it's been hard letting go of that.

Also the ecologists are not at all interested in the money side – even though we are a commercial business.

They're just interested in the animals, so it can be hard for me sometimes to control costs for our clients.

I've been surprised at how many other organisations there are out there that do what we do. The competition is fierce.

I enjoy the job, although it can sometimes be more frustrating than when I was working in IT; but it can also be much more rewarding."

'We give staff extra holiday for every day they cycle to work'

Joanna Foy is environmental officer for Forster, the communications and PR company, which has 51 staff at its central London offices. She moved to this role two years ago from a post as assistant to the chief executive.

"I'm responsible for the targets on reducing emissions and improving our all-round environmental performance that we set ourselves after our annual environmental audit performed by an external consultant.

I encourage staff to take up initiatives, for example our cycling and walking-to-work scheme. We give staff five minutes extra holiday for every day they cycle or walk to work, which means if they do that every day, they get an extra two and a half days holiday.

The company bought two Brompton (collapsible) pool bikes for staff to use when going to meetings in London. The reaction has been really positive. Cycling on business trips has gone from zero to 10 per cent in six months.

Another way we try to reduce our energy usage is by giving out sweatshirts to staff in September and October, so we can hold off turning the heating on for a month or so. And at a company meeting last year, we gave out a winter survival kit, consisting of a woolly hat, some knitting needles and instructions on how to knit, and also some vitamin C tablets and echinacea, to keep the immune system boosted.

We've also installed a wormery, which sits on a balcony, to turn our organic material – including apple cores and banana skins – into compost.

And I'm responsible for our supplier screening, making sure they observe standards that come up to our policies. That gives me lots of interaction with other organisations, and, with sustainability events I attend, helps me keep in touch with other ideas."