It has to be the first rule of pragmatic management: always spend your budget, because if you don't it'll only get cut.

It is the reason that spending on training courses and adverts and office refurbs and corporate hospitality always seems to get authorised just a few weeks before the end of the financial year as managers rush to prove to their superiors that they need every last penny of their budget.

Even when bonuses are on offer for those who come in under budget, canny managers know it makes more sense to exceed their budget by a small amount rather than risk sparking thoughts at board level that if you managed to spend so little this year you won't mind an even smaller budget next year.

However, while such pragmatism makes sense from each individual manager's perspective it also encourages corporate profligacy and poses a serious challenge to green investments, many of which promise to reduce costs and thus potentially lead to budget cuts.

Every manager knows that budgets equals power, so it is understandable that a facilities director should look at an sensor-based air conditioning system that promises to slash management costs and electricity bills, for example, and ask if it is really a good thing for their long term standing in the business.

Equally an IT chief keen to do their bit for the environment by extending their hardware refresh cycles by a couple of years would be understandably deterred if they knew such a decision would mean they were left with less investment cash to play with.

This problem can of course be resolved if senior execs force middle managers to drive through green investments regardless of the impact on their long term budgets, or if bonus schemes and budget allocations are correctly structured to ensure managers can see value in investments that deliver cost savings and are allowed to reinvest any savings they achieve.

As Gary Meades, environmental affairs manager at British Airways, observed at this week's Kyocera Green Card conference, if a departmental manager does not have to handle waste disposal costs they have no incentive to pay more up front for kit that will last longer.

However, budgets and bonuses that break down departmental fiefdoms and strong board level leadership that drives through green investments are sadly all too rare, meaning managers often have to find their own way to implement cost saving green investments without jeopardising future budgets.

The answer, according to Kyocera Mita's UK head of marketing Tracey Rawling Church is to simply extend managerial pragmatism a step further and package sustainability projects that save money, such as energy efficiency measure, with those green projects that require investment but deliver no clear cost saving, such as green subsidies for staff or carbon offsetting.

"It means that you get a double environmental benefit and it remains cost neutral," she observed.

It may not be an ideal scenario when so many green business projects are capable of delivering substantial cost savings, but with middle managers often protecting their budgets with the intensity of crazed tigers it is a realistic means by which they can authorise green projects and still protect their budgets for the years ahead.