During the summer of 1973, aged 12, I went on a family holiday to Cornwall. I have many vivid memories from that trip and like many abiding recollections some of the most powerful come from smell. As I bobbed about one day in the surf by the mouth of a little river on Porth Beach near Newquay there was a pungent aroma coming from the water.
I didn't know what the smell was but my grandmother found out, by collecting mussels from the rocks. That evening back at our holiday house she cooked them and after eating her newly harvested shellfish soon became violently sick - because the smell in the water was sewage.
Back then in the early 1970s it was perfectly legal to discharge minimally treated human faeces into the sea. No longer though. Why? Because of EU rules that outlaw this mad practice. Plenty of other environmental benefits have come from rules negotiated in Brussels as well. Indeed, if you look back, the EU has been the most important factor shaping the quality of Britain's environment during recent decades. There are many examples.
During the mid 1990s I was the leader of Friends of the Earth's biodiversity and habitats campaign. One of our top priorities back then was to secure the effective implementation here in the UK of the new EU Habitats Directive. We worked with leading experts to publish a list of natural areas that we felt met the criteria for protection under the new European rules. We lobbied then Environment Secretary John Gummer (now Lord Deben) to not only embrace an ambitious list of sites to be covered by the new Directive but also to come forward with strong UK rules to look after them.
It proved to be an important moment in 1994 when the places to be designated were announced and new regulations to implement the Directive were adopted by Parliament. Many of our most treasured landscapes and wildlife were from then on better protected by that law - from Welsh sand dunes to English meadows and from Scottish pine forests to Northern Ireland's raised bogs. We have enjoyed the benefits since, with our last natural treasures more effectively conserved than would have been the case under any domestic laws. And today there is an on-going process extending that high level protection to habitats in the sea, which will help improve the fortunes of many wildlife species that live around our coasts, including seals, sea horses and dolphins.
Even before then, back in the early 1980s, the backbone laws to protect Britain's wildlife, the 1981 Wildlife and Countryside Act, were passed by Mrs Thatcher's first Government so as to enable the UK to meet the terms of the then new European Birds Directive.
When I began my work as an environmentalist a few years later one of the biggest threats to nature in Britain was acid rain. It was European laws that required us to clean up that pollution too, especially sulphur and nitrogen emissions from coal-fired power stations and major industrial sources, in the process enabling woodlands, blanket bogs and rivers to begin recovering their wildlife, and for all of use to breathe cleaner air, avoiding tens of thousands of premature deaths in the process.
Today I work as an advisor to a wide range of companies, including those in the UK water supply sector. They are planning a massive programme of investment that will further clean up our rivers, wetlands and coasts, but only because of EU law. Other companies I work with are devising strategies to cut air pollution, not least because of the need to comply with EU rules.
We've also had to up our game on recycling because of EU limits on landfill, and to come forward with measures to recycle defunct cars and waste electronic products. I can't imagine any scenario where that would have happened without us negotiating such rules with partner countries in the European Union.
On the global agenda too the EU has been a powerful force for good. At successive climate change summits that I've attended it has been the EU that has been the most progressive voice from the developed world. During the last year's Paris climate change negotiations Britain mobilized its impressive diplomatic network to build common cause toward the strong agreement that resulted there. Our advocacy was rendered the all more weighty because we could present our view as part of a far bigger and stronger front, one built on the united position of 28 European Union member countries. We would never have had the impact we did as one country alone.
There have undoubtedly been some downsides for the environment resulting from EU agreements, including in relation to farming and fisheries. But even here there is cause for some optimism as to the prospect for positive change, not least coming from the revised Common Fisheries Policy adopted in 2014.
While I've had repeated cause to criticize the Common Agricultural Policy it is important to ponder what UK policy might be should we leave the EU. From the many meetings with ministers and prime ministers that I've had over several decades I'd say we shouldn't expect the a UK-only policy to promote organic, local or sustainable food production. It would be a policy based on free market ideology in which nature and wildlife would have little or no sway. I've not seen any evidence to suggest otherwise.
The world is different to how it was when we joined the European Economic Community in 1973, but one thing is for sure - the environmental challenge is bigger, more complex and even more linked to our health, welfare and wellbeing that it was back then. And it is an agenda that requires long-term thinking, not least to enable the many companies who need to invest in a cleaner greener future - in the energy, water and waste sectors, among others - to make the right decisions.
It might be argued that we could have a good environment if we were outside the EU, but that view is surely a triumph of hope over experience, and indeed evidence.
We have no reason to believe that Westminster outside the EU would do very much to protect our environment. Our current Government frequently tries to push things backwards - including recent attempts by George Osborne to weaken the Habitats Directive. Many media outlets are happy to parrot the 'get rid of the green crap' line and to repeat the spurious view that protecting our environment to the standard that we do (insufficient though it is) is so much red tape. Many of he most prominent campaigners for us to leave the EU are climate change deniers and if given opportunity would gleefully do away with environmental rule across the board - on pesticides, wildlife, water and more.
Make no mistake, if you like to walk by clean and wildlife-rich rivers, to swim in the sea, breathe fresh air, enjoy birdsong and butterflies and for your country to be a positive force in meeting global challenges, then you must vote to remain in the EU. There is no reason at all to believe that leaving would improve the state of where we live, or indeed the global environment upon which we all depend. On the contrary, it would take us backwards.