Environmentalist and theologian Ruth Valerio made a commitment this Lent to reduce as much as possible the amount of plastic she uses. It's a commitment that clearly resonates with others as a Facebook group she set up on exactly this topic, called Plastic-Less Lent, has attracted nearly 4,000 people.

And it's not only of interest here in the UK; members of the group are spread over 55 countries. Where they call home may look different but their concern is the same: how to cut plastic from their lives and make choices that will be kinder to themselves and to the planet.

It's a journey together in which every day through Lent, they have been sharing their own tips, advice and experiences in going plastic-free.

Many of the suggestions are simple, such as buying reusable water bottles or shopping bags, and choosing loose fruit and veg at the supermarket instead of those come wrapped in plastic.

One post is from a mother who has committed to making her own hummus at home instead of buying the plastic tubs from the store each time. Another post charts one person's first foray into homemade deodorant.

Other posts encourage simple activism, like contacting supermarkets and magazine publishers to encourage them to ditch plastic wrapping.

Far from being insignificant, Ruth is hugely encouraged because she says it is the small things that can add up to have a really big impact.

There's lots of things people can do, she says, like switching back to good old bars of soap instead of bottles of hand wash and shower gel, and swapping plastic toothbrushes for bamboo ones.

"It's so important for people to know that every little step really does make a difference because each thing we do is one less item of plastic ending up in the landfill or the oceans or in the rivers somewhere," she says.

"And it also makes a difference because when we reduce our plastic usage, we will be sending a message to governments and businesses that this is something we care about and want them to take action on."

It can sometimes cost more to buy products that are kinder to the environment, she admits, but she is asking those who can afford it to pay that little bit extra in order to move away from plastic.

At the same time, she suggests shoppers even speak to store managers to ask them about their pricing policies so that plastic-free items, particularly groceries, are priced the same as or less than those that come wrapped in plastic packaging.

"We shouldn't be penalised for not using plastic," she says.

It's so important because plastic consumption is increasing around the world, not decreasing, she says.

The damage being caused by plastic in our oceans is well-documented, but there are other problems with the amount of plastic consumption.

"It's harmful in terms of the energy it uses to produce the plastic and plastic, of course, is petroleum-based, so it requires oil in order to manufacture it. So all the way through from how it's created and what it's created from, to how it's then used and thrown away, creates problems."

There's the impact on health too.

"Where plastic isn't disposed of, it's left sitting around and collects water," she continues.

"These pools of water are breeding grounds for flies and mosquitoes, not to mention the rats. This all leads to increased dengue fever, cholera, malaria, diarrhea and typhoid. It causes so many problems."

One of the causes behind the huge amount of plastic in our oceans is the lack of proper waste disposal facilities in developing countries.

"Something like two billion people in the world don't have their waste collected, and uncollected rubbish causes death, disease, flooding, climate change - all of which are critical issues," she says.

"One statistic I saw recently estimates that about 50-70% of plastic waste in the ocean is coming from developing countries. That's not to put the blame on them but it highlights how important it is that we help them to put good waste management systems into place."

That's one of the reasons she is working with Christian development agency Tearfund in Pakistan, where around two-fifths of the country's estimated 20 million tonnes of rubbish each year goes uncollected.

That rubbish is either burnt in the streets or thrown into the rivers where it builds up and causes flooding and health issues.

The problem is particularly acute along the Indus River, whose delta has become a collection point for uncollected waste flowing out from some of Pakistan's slums.

According to one recent study, the Indus River carries the second highest amount of mismanaged plastic debris to the sea out of all the world's rivers.

"By starting to tackle the issue at source, you start to tackle the problem in the oceans as well," says Ruth.

Tearfund recently launched an appeal in aid of building new recycling hubs in communities along the Indus River. The campaign is being supported by the UK Government, which has pledged to match donations up to £3 million.

The charity has already seen huge success in its existing recycling hubs in the country, which, according to Ruth, have been recycling around 80-90 per cent of waste from surrounding communities.

"Within a few years, they've become self-sustainable and so we have this triple win of environmental benefit; the benefit to people's health; and then livelihoods, because it creates jobs for people in a context where unemployment is a massive problem."

As part of the Matched Giving Appeal, Tearfund has been inviting people to take the Plastic Pledge to give up one single-use item of plastic.

"The big issue we're wanting to focus on is single-use plastic and our culture where it's become so normal to buy something made from plastic and then to throw it away," Ruth says.

"We want to see recycling increase but we need to take a step back before that and reduce the amount of plastic we use in the first place."

There are positive signs that businesses are catching on to the problem of plastic. In the last few years, plastic bags have largely disappeared from shop checkouts, with the exception of reusable ones that shoppers have to pay for.

And coffee shop chains, which often use plastic lids and cutlery, are increasingly encouraging customers to order their drinks using their own reusable cups.

But governments need to step up too, Ruth says, particularly in light of the concerning IPCC report last year, which warned of a climate disaster if global warming is not kept to 1.5C of pre-industrial levels. The current trajectory is a global temperature increase of 3C.

"We need to see companies taking action and turning the tap off at source but we also need to see governments taking action and they can do this by putting into place policies that make it undesirable for a company to use plastic cheaply and they can use some of their aid money to support developing countries in putting into place proper waste management systems," she says.

Advocacy is one area where Ruth believes Christians can play an important role.

"We need to care because this is having a devastating effect on people living in poverty and the world, and it's an absolutely essential part of what it means to be a Christian, to care for the world and what God has made - this is not an optional extra but at the heart of our discipleship.

"So I want to ask everyone to be getting engaged in campaigns calling on our governments to take climate change seriously and to honour their commitments to the 2015 Paris Agreement."

As for all those water bottles collecting at the sides of our roads and in our parks, beaches and oceans, she has these words: "We don't need them! Let's buy a reusable one and consign them to history!"