Tyres have an enormous impact on the environment. What can be done to produce and dispose of them more efficiently? Tom Heap reports.

Producer: Anne-Marie Bullock

From the cattle shed to the racetrack, ammonia is having a moment. In the wrong place it's a dangerous pollutant, in the right place it's a clean fuel for your car. Ella McSweeney and Peter Hadfield report on the two faces of the gas chemists know as NH3.

The increasing global demand for milk means more big dairy herds. More cows means more dung and urine. Mixed together they produce ammonia gas which contributes to urban air pollution and destroys sensitive habitats. In Ireland scientists have spotted big problems in peat bogs. The mosses which help create the carbon-grabbing peat are dying off in areas down-wind of dairy, pig and chicken farms. Farmers are being asked to change the way they store and spread their slurry, but it could be too late for some of the island's most vulnerable bogs.

Meanwhile, in Australia they're exploiting some interesting properties of ammonia. Environmentally-friendly hydrogen-powered cars have been around for years but they've failed to take off because hydrogen is costly and awkward to transport. By contrast, ammonia is very simple to move around from refinery to fuel station. Splitting the N from the H is straightforward, giving drivers a source of fuel that emits only water from the exhaust pipe.

So can ammonia complete its journey from environmental villain to green hero?

Producer: Alasdair Cross

2019 is the 70th anniversary of the legislation that created the first National Parks in the UK. At this crucial moment for the future of our countryside, Tom Heap asks how our best-loved landscapes can work better for people and wildlife. There are now 15 National Parks – all are protected areas because of their beautiful countryside, wildlife and cultural heritage. However, much has changed since the original legislation and many of these landscapes face significant challenges, including declining wildlife, a need for housing and poor public access. Tom visits two very different parks, the Cairngorms and the South Downs, to ask communities how they think National Parks should be improved to meet the needs of the 21st century. He considers some of the key issues; such as how to balance agriculture with enhancing and connecting habitats and how to deliver rural development and housing in protected landscapes.

Producer: Sophie Anton

The heat contained in the top 3km of the Earth’s crust could power the planet thousands of times over. Despite that, less than 1% of the world’s electricity comes from geothermal energy. That may be about to change.

Near Redruth in Cornwall a 3 mile deep hole is being dug- it will be the deepest in the UK. Cold water will be pumped down to the 200 degrees hot rocks below, the hot water returning will drive turbines to provide electricity for thousands of homes. Nearby, the Eden Project and the seawater lido in Penzance are building their own geothermal plants.

But Cornwall is just the tip of the iceberg. Geothermal electricity was first produced in 1904 at Larderello in Tuscany. Today Enel Green Power supply a third of the region's electricity from natural steam and they have plans to get much bigger, exploiting an extraordinary bit of chemistry. When water goes above 374 degrees centigrade and 221 bars of pressure it becomes a supercritical fluid. This contains five times as much energy as 200 degree water, transfers energy twice as efficiently and has a lower viscosity. Overall, you can theoretically get ten times more energy than from a similar conventional borehole.

The new technology also promises more efficient geothermal energy in regions far away from geological hot spots like Iceland and Italy. The only fly in the ointment is that some techniques involve creating bigger fractures in the rocks. Experiments at Basel in Switzerland provoked an earthquake. So can the incredible potential of new-gen geothermal be exploited without provoking protests?

Producer: Alasdair Cross

Climate change is hard to depict. Polar bears on melting ice caps are far away from everyday life and the data is often complex and confusing. So could art in its broadest sense help us to understand the implications of global warming and environmental degradation? Tom Heap takes a look at how the creative community is responding to what is arguably the biggest threat of our time and asks if art can succeed in eliciting a response where science has failed.

Music and visual arts which make climate data sets tangible, clothing which make pollutants visible and artists who make their creative response a form of protest. These are just a few of the ways in which artists are responding to environmental issues but it remains to be seen if these visions can impact our collective beliefs and behaviours.

Over the last decade, wet wipes have become ubiquitous. There's a wipe for almost everything, from faces to furniture, and it's a multi-million pound industry. But our sewerage systems are paying the price. Tom Heap goes on a call-out with the teams whose job is unblocking the drains - and finds that the culprits are usually wet wipes. It doesn't stop with the sewers: wipes can now be found in their millions on our beaches and in our rivers - where they are affecting wildlife, and in some cases even changing the shape of the riverbed itself. Water companies say that nothing but pee, poo and paper should be flushed down the toilet. Many wipes are labelled "do not flush" - but Tom talks to experts who cast doubt over whether even the ones marked "flushable" really are.

Producer: Emma Campbell

What have wetlands ever done for us? Apart from providing fresh water, carbon storage, flood mitigation, wildlife habitat and much more....they are said to be critical to human and planetary life. But a recent report claims despite this these ecosystems are disappearing three times faster than forests. Around 35% of the worlds wetlands were lost between 1970 and 2015 - but the UK lost most of its before then. So why don't we care? Are a 'bunch of bogs and ditches' less valued than a romantic forest?

Tom Heap finds out what wetlands are and what they do for us and if policy makers and decision-makers need to value them more highly, should we too? The positive news is wetlands can be created and improved - both on a large scale and in our own gardens and neighbourhoods. Is it time to make some noise for the wonders of wetlands?

Produced by Anne-Marie Bullock

China's $900bn Belt and Road Initiative is taking Chinese money, expertise and workers all around the world. From South-East Asia all the way to South America, Chinese influence can be spotted at construction sites for roads, dams and railways. Evidence is mounting that this is bad news for rare and endangered species. Local people discover that Chinese workers have an appetite for the skin, bones and teeth of rare creatures for use in so-called Traditional Chinese Medicine. A market is established and before long an illicit trade is established, reaching all the way back to China.

The Chinese government has just announced a partial reversal of its 25 year ban on the sale of rhinoceros and tiger parts. That decision is expected to boost the illegal trade in endangered species.

Peter Hadfield has travelled across the world from the Kazakhstan steppe to the markets of Hong Kong, in search of the species threatened by the trade and the buyers of body parts. He discovers a new drive from scientists to create alternative compounds and asks if consumers will accept an artificial option.

Producer: Alasdair Cross

Could the war on plastic have unintended consequences for the environment? Tom Heap reports.

Producer: Sarah Swadling

The environment affects us all so should gender matter when we consider how best to save the planet? Lucy Siegle and Tom Heap take on the gender divide to find out how global warming has a disproportionate impact on women and how solutions which put women in charge can be highly effective in saving carbon as well as creating equality.