Wherever you live, there is surely some countryside or coastline not too far away that you are proud of. A place unique in its beauty, perhaps even somewhere that people from all over the world visit just to see for themselves. There are likely plants and animals thriving there that you would struggle to see anywhere else on Earth. They have found a spot that suits them, literally, down to the ground.

Quite possibly, you have memories of getting to know places like that as a child. They may have left an impression on you, one that has never quite faded away.

Someone else who had that kind of experience was the English poet William Wordsworth. In a poem that he worked on from 1798 until his death in 1850, he wrote about how being in touch with Nature had shaped his whole life.

"With deep devotion, Nature, did I feel,

In that enormous City's turbulent world

Of men and things, what benefit I owed

To thee, and those domains of rural peace […]"

We can probably all relate to this in some way. The lengthy poem, known as The Prelude, has many moments like this in which Wordsworth essentially thanks Nature for the influence it had on him. A similar respect for Nature is shared by many of the greatest human minds, from Plato to Beethoven.

But while Wordsworth was writing his masterpiece, a fellow devotee of Nature was carving a path through the rainforests of what is now Venezuela. That man was Alexander von Humboldt, a Prussian naturalist and explorer. What he saw in 1800 in the Aragua Valley disturbed him deeply.

The hills all around, which the locals told Humboldt had been full of greenery a few decades before, had been stripped of trees. The forest was gone. Now, whenever heavy rains came, the water was washing away the very soil of the hills themselves. Nearby rivers were also fed with greater volumes of water, and the resulting torrents were damaging yet more land downstream.

The floods have catalysed both public and political change

In her magnificent biography of Humboldt, The Invention of Nature, the historian Andrea Wulf explains that this is where Humboldt started to realise that people did not just have the capacity to enjoy Nature. We could also harm it.

"The action of humankind across the globe, he warned, could affect future generations," Wulf writes.

She recounts how, just a few weeks later, Humboldt stumbled on some Spanish monks in the Orinoco rainforest. They were lighting their huts by burning oil from turtle eggs. The local population of turtles was sadly dwindling as a result.

In that age of Romanticism, humanity was developing new ways of expressing admiration for Nature, and at the same time realising that we have a responsibility to look after it. Wordsworth and Humboldt both knew this. But nowadays many of us seem to have forgotten.

In 2014, local flooding devastated a number of towns in the UK. Polls later reported found that public attitudes to Nature suddenly spiked immediately afterwards. "The floods have catalysed both public and political change," wrote Geoffrey Lean in the Telegraph.

We produce more rubbish than any other pollutant

However, that newfound enthusiasm quickly fell away in subsequent polls. That initial surge of interest in nature had been wasted.

Unfortunately, many of us are pretty wasteful. In the 19th Century, global waste production rose tenfold and is predicted to double again by 2025. The growth in the human population is part of the explanation, but cannot account for all of the extra rubbish.

We produce more rubbish than any other pollutant. Shamefully, huge amounts of plastic now roam the oceans, where they threaten marine life by blocking out the sunlight that nourishes plankton and algae.

Temperatures around Earth are changing, too.

The surface of the planet is getting warmer. This has been confirmed by measurements all around the globe, going back many decades.

The effects of our mistakes can be bigger than we might expect, because of the Law of Unintended Consequences

One of the big causes of this is the presence of gases in the atmosphere like carbon dioxide and methane – which many industries release in great volumes as waste products. These gases absorb light from the Sun and re-emit it as heat, instead of allowing that energy to be released back into space. This effect was discovered in the early 19th Century. It is so well-known that heat-seeking missiles account for it when calculating their trajectories.

Another substance that has this warming effect is a little-known gas called sulphur hexafluoride. Its effect on the climate is smaller than that of carbon dioxide, simply because there is less of it, but pound for pound it is actually much more potent.

A few years ago, the United States Department of Energy set out to stop the wasteful leakage of this gas from its facilities. In 2013 they reported a big success: they had cut annual leaks by 35,000 pounds, about half the total, simply by taking better care.

When we do not take this sort of care, we can inadvertently hurt the things we value.

Even a small change in the average annual temperature, just 1 or 2C, can be enough to impact the survival of a treasured species. North America's monarch butterflies, which are famous for their huge migrations, are one of the species that seem to have been harmed by warmer temperatures.

Sea level rise has serious implications for national security

The effects of our mistakes can be bigger than we might expect, because of the Law of Unintended Consequences. For example, as things get warmer the Arctic sea ice melts. As a result, there is less sea ice to reflect the Sun's rays back into space – which means temperatures rise even more, and even more sea ice melts.

We are also facing a rise in sea levels, which poses a threat to low-lying coastal areas such as Miami, Florida. This too can be attributed to our careless release of carbon dioxide, because the additional heat is making seawater expand: the oceans have literally swollen over the last century.

In 2016, retired General Ron Keys, formerly of the US Air Force, pointed out that sea level rise has serious implications for national security.

"We have 19 bases that we consider jewels in our crown of capability that are going to be affected by sea level rise," Gen. Keys told the annual Common Good Forum.

"It is mankind and his activities which are changing the environment of our planet in damaging and dangerous ways," said UK Prime Minister Margaret Thatcher

Gen. Keys also argued that, as communities around the world become more susceptible to flooding, militaries will be more frequently tasked with rescuing them. That would mean the militaries becoming less available for frontline defence.

Environmental changes like these can unleash the worst parts of human nature.

In Central Asia, rising temperatures have depleted glaciers in the mountains of Kyrgyzstan and Uzbekistan, among others. Farms in nearby valleys rely on water from these glaciers, but there is less and less available. The farmers are now beginning to quarrel bitterly over access to the remaining water.

We do not know how situations like this will play out, but they are hardly a stabilising influence. In 2016, US national security experts released a report arguing that changes like this, which are happening around the world, pose a "significant risk to US national security".

Indeed, many of our most celebrated leaders believed that we had a duty of care towards Nature.

"It is mankind and his activities which are changing the environment of our planet in damaging and dangerous ways," said UK Prime Minister Margaret Thatcher in a rousing speech to the United Nations General Assembly in 1989. Mrs Thatcher mentioned the harm caused by pollutants, the destruction of forests, and the warming effect of gases in our atmosphere. "Mr President, the evidence is there. The damage is being done."

Burning less coal does not just reduce long-term climate warming: it also immediately cuts toxic air pollution and smog

US President Ronald Reagan's policy advisers said similar things.

"A veil hangs ominously over the Earth, from pole to pole, over all the continents, and over the oceans," said James C Greene, Science Consultant to the US Congress's Committee on Science and Technology. "To a significant degree, man has put it there. It is called, simply enough, carbon dioxide pollution."

More recently, the former Republican Governor of California Arnold Schwarzenegger has argued that investment in renewable energy and cleaner forms of transportation, such as American-made electric cars, would allow us to live both responsibly and profitably. The good news is that there are lots of things that we can do to rescue Nature, and improve our own lives in the process.

Technologies to harness cleaner energy sources are currently being developed by our top entrepreneurs and universities. Investing in them, rather than subsidising dirty and wasteful technologies, would make a big difference. Burning less coal does not just reduce long-term climate warming: it also immediately cuts toxic air pollution and smog.

It will take real leadership to protect the places we fell in love with as children

We could also all save a lot of money by using less energy in the first place.

"US citizens spend more money on electricity to power devices when off than when on," as Scientific American noted. "Televisions, stereo equipment, computers, battery chargers and a host of other gadgets and appliances consume more energy when seemingly switched off, so unplug them instead."

Restoring forests could also help, by locking up carbon dioxide that would otherwise escape into the air. Doing so has many other advantages: we would see less of the kind of damage to land and wildlife noticed by Alexander von Humboldt 200 years ago.

Ultimately, it will take real leadership to protect the places we fell in love with as children.

Governments and large organisations have the power to help us introduce clean energy to our homes – and to strike deals to reduce the emissions of waste gases like carbon dioxide.

There are many ways that this could be done in principle. One approach, which is currently being championed in the US by some Republicans and business leaders, is to tax carbon dioxide emissions.

If we do not clean up our messes, who will?

This need not be an extra tax: it could replace existing taxes, such as income tax. In the case of the US proposal, the idea is to pay all the revenues back to ordinary people.

One country that has tried a similar approach is Ireland, which has used a carbon tax to make it more expensive to burn dirty fuels than cleaner ones.

"This has allowed us to avoid (more) increases in income tax, which would have further reduced disposable income, increased labour costs and destroyed jobs," notes Frank Convery, an economist at University College Dublin.

Ireland's harmful gas emissions have since fallen.

There have always been people calling for us to take responsibility for the world around us. People today may seem less interested in protecting Nature, but maybe this is because we are all isolated in our social media bubbles and are not hearing what everyone is saying.

Maybe now it is time to look around at the countryside and wilderness we are so lucky to have – often just an hour away – and start making changes to ensure it will not soon disappear.

It has been a long time since anyone wrote poems like Wordsworth, but his words are still there for us to read. They are a reminder to us that sticking up for Nature is surely a moral duty. After all, if we do not clean up our messes, who will?

If we do, perhaps we can say, as Wordsworth did:

"Prophets of Nature, we to them will speak

A lasting inspiration, sanctified

By reason, blest by faith: what we have loved,

Others will love, and we will teach them how."

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