We undervalue food in this country, yet Britain has beautiful food and beautiful growing conditions. It is astonishing the range we can grow.

My basic philosophy is never do anything with the word 'celebrity' attached to it. Without being overly pompous, if you have worked hard to have an audience trust you a bit, why blow it? That is my currency.

The horticultural industry is unimaginative and dominated by vast, supermarket-like outlets. But the small nurseries and growers remain - praise them with your wallets, not your memories.

A healthy plant is one that adapts best to the situation in which it finds itself. There is no objective measure of this.

Is it 10 years, 20, 50 before we reach that tipping point where climate change becomes irreversible? Nobody can know. There's clearly a probability distribution. We need to ensure this planet, and we need to do it quickly.

The basic science is very well established; it is well understood that global warming is due to greenhouse gases. What is uncertain is projections about specifics in the next few decades, by how much will the climate change.

It's very clear that global climate change is occurring on earth, but it's also been very clear that that has always happened on earth. We've always had a changing climate on earth. We all know about ice ages. We know when our continent was covered with ice sheets. We know glaciers come and they go. It puzzles me that people forget that.

Climate change is hugely exacerbated by changing patterns of how we choose to live, often in danger zones such as extremely vulnerable coastal zones - from New Jersey to the Philippines. This enormously increases the economic and human costs of hurricanes, rising seas and changing weather patterns.