I believe that if politics is about anything, it should be about improving people's lives and bequeathing something better to our children than we ourselves inherited. If internationalism is about anything, it is about doing that for people around the world regardless of where they live. That's what environmentalism and sustainability mean to me.
No sensible government can govern in these challenging times without putting tackling climate change at the core of what they do. It must be done consistently over time, beyond just the confines of one parliament, across all government departments led by the prime minister. Ed Miliband, Caroline Flint and I all understand that. I thought that David Cameron understood this.
David Cameron travelled to Norway to see the impacts of climate change for himself, and returned urging the British people to "vote blue, go green". His record since 2010 has not matched the rhetoric before the election. David Cameron has gone from promising to lead the "greenest government ever", to ditching the "green crap".
The committee on climate change - the government's own independent advisors on climate - have warned that without taking new steps to reduce our emissions, the UK is likely to miss the carbon targets committed to by the last Labour government.
David Cameron has given top jobs in government to known climate change deniers. He made Owen Paterson his environment secretary, a man who argues that climate change will benefit Britain. Michael Fallon was the Conservative Party minister of state for energy and climate change who referred to climate science as "theology".
The Conservative Party's record on flooding is the clearest example of the damaging impact of their failure on the environment.
After the 2007 floods, the Labour government learned lessons and built a cross-party consensus to protect the country from severe flood risk in future. We raised spending accordingly and with the support of David Cameron in opposition. On coming into office Cameron's Tory-led Government shattered the post-2007 consensus. They cut the funding for flood protection from £670million in 2010/11 to £576million in 2013/14. They slashed the budget for adapting to climate change by 40% and even removed 'prepare for and manage risk from floods' from Defra's departmental priorities.
Five more years of David Cameron as prime minister would see things get even worse. The committee on Climate Change has calculated that current Tory plans will put an extra 330,000 properties at serious risk from flooding by 2035. On average, that's over 80,000 new properties at serious risk of flooding every five years.
Britain needs a government that takes the increasing risk of flooding seriously and tackles it over the long term. That's why the next Labour government will reprioritise flooding as a core responsibility of Defra; produce a new National Adaptation Programme; and establish an Independent National Infrastructure Commission to identify the UK's long-term infrastructure needs, including flood protection.
Air pollution is another environmental issue David Cameron has totally failed to address. Air pollution causes 29,000 premature deaths a year in the UK and is one of the primary causes of cancer. Scientists have warned that poor air quality in Britain's most polluted cities is stunting the growth of children and damaging babies' lungs in ways which will affect them for the rest of their lives. Air pollution is a key issue of environmental inequality because there are higher concentrations of pollutants affecting people in deprived areas.
What is politics for if it can't address a crisis like this?
The UK currently has one of the worst records of any European country for exceeding EU air pollution limits, and next year we could face fines of hundreds of millions of pounds for our failure to meet targets for safe air quality. Yet the government's approach to tackling air pollution was described by the Healthy Air Campaign (which includes organisations such as the British Heart Foundation and Asthma UK) as "designed to mask the true scale of England's air quality crisis rather than make any attempt to solve it". Last December, the government had to scrap their consultation on 'Local Air Quality Management' because the evidence suggested it would have made the problem worse and it now has no strategy whatsoever.
The government legislated in the Localism Act 2011 to force Local Authorities to pay any EU fines which are levied against the UK for missing European targets in their areas. They have localised the responsibility for paying the fines without setting out a national framework for action to tackle the problem. That's why on Monday I announced that as environment secretary I will deliver a national framework for Low Emission Zones to enable local authorities to encourage cleaner, greener, less polluting vehicles to tackle this problem.
It is the duty of government to protect people, whether it be from floods caused by a changing climate or the threat of air pollution. David Cameron has failed in government to show that he understands that. Next December should see the UK government working hard to get a global deal on limiting emissions in Paris next December. Let's hope for people today and for future generations that it's a Labour government led by Ed Miliband.
Maria Eagle is the Shadow Environment Secretary