The title says it all, the future for all of us is green. Ironically, this will mean that the Green Party will become surplus to requirements - certainly in their current political form. Let me explain.
Nearly all of our current environmental troubles can be directly linked to the global population explosion - environmental damage is related to the demands placed by ever-increasing population. For example, more people leads to more cars, which leads to more use of petroleum-based products for combustion. Since the environmental problems are proportional to population, that implies that to manage or resolve most of these issues, we will require the majority of the worlds population to take responsibility for their actions. Governments can only play a part in this, and as events have unfolded with, say, Kyoto recently, even individual governments cannot come to agreement.
The only way in which we, as the resident sentient beings on this planet can hope to reverse some of our impacts on the planet is for everyone to take responsibility for their actions (note that I don't necessarily accept various findings on climate change, but it is undeniable that increased population is having increased impacts on the planet).
In their current incarnation, the Green Party are filling a useful role to increase the awareness of local and global environmental issues. However, as long as environmental issues remain the domain of a special interest party - we, as a country, are not doing enough for the environment and for our future. My thought is this - we will only know that we are doing enough for environmental issues when consideration of environmental issues are infused throughout planning, decision-making, policy and all our individual actions. Funnily enough - I believe that the Green Party would serve a more useful purpose by getting into and working with the current general-purpose parties and working on environmental issues from the inside and collaborating with the other portfolio holders.
Of course, whilst planning and policy at a central government level is moderately important, the most important actions for us to take are our individual actions. I recently reverted to biking to work, which I haven't done since school. My reasons were twofold - it is better for the environment, and its better for me (especially for someone that leads a relatively sedentary lifestyle). Naturally, I can't bike to work every day, as there are always days that I require a car, but I am really trying to minimise my usage of it. I have also been making much greater use of public buses where possible. But I'm not going to suggest this as a solution for everyone. It is your own responsibility to look at your life and how you can take a more friendly approach to the environment.
No matter what the government does however, individuals will not change unless they want to. Even if people have to pay more tax on petrol to appease the Kyoto gods, they will pay it - just like people will keep paying higher prices on alcohol and tobacco as the levies and duties are increased. It is because of this, that we need the environmental ideas that the Green Party promotes to move out of a special interest party, and for the main parties at least to incorporate environmental thinking in their policy. This would actually be beneficial as the Green Party would no longer be the sole promoter of environmental ideas, and would produce greater competition and analysis of environmental policy.
No, this won't happen overnight, and it may take many years. But over time, I think it would be in the country's best environmental interest for the current Green Party personnel to either be subsumed into the mainstream political parties, and for them to create an environmental think-tank that provides research and guidance into international trends and development of environmental policy in New Zealand. The continuation of the Green Party in its current form will be all the evidence we need of our failure to take better care of the environment.