World Water Day, celebrated on March 22 every year, is about focusing attention on the importance of water. This year’s theme, ‘Nature for Water’, explores nature-based solutions to the water challenges we face in the 21st century.
The United Nations has warned that environmental damage coupled with climate change is driving the water-related crises we see around the world. Floods, drought and water pollution are all made worse by degraded vegetation, soil, rivers and lakes. When we neglect our ecosystems, we make it harder to provide everyone with the clean water they need to survive and thrive.
Nature-based solutions have the potential to solve many of the planet’s existing water challenges. However, more needs to be done with ‘green’ infrastructure, to harmonize it with ‘grey’ infrastructure wherever possible.
Planting new forests, reconnecting rivers to floodplains, and restoring wetlands will rebalance the water cycle and improve human health and livelihoods.
According to a recent UN report on the state of the world’s water, more than 5 billion people could suffer water shortages by 2050, due to climate change, increased demand, and polluted supplies. The comprehensive annual study warns of conflict and civilizational threats unless actions are taken to reduce the stress on rivers, lakes, aquifers, wetlands and reservoirs.
The World Water Development Report – released in drought-hit Brasília – says positive change is possible, particularly in the key agricultural sector, but only if there is a move towards nature-based solutions that rely more on soil and trees than steel and concrete.
The World Water Forum is the biggest single gathering of policymakers, businesses and NGOs involved in water management. It is being held from March 18-23, in the southern hemisphere for the first time, and is expected to draw 40,000 participants.
“For too long, the world has turned first to human-built, or ‘grey’, infrastructure to improve water management. In doing so, it has often brushed aside traditional and indigenous knowledge that embraces greener approaches,” says Gilbert Houngbo, the chair of UN Water, in the preface of the 100-page assessment. “In the face of accelerated consumption, increasing environmental degradation and the multi-faceted impacts of climate change, we clearly need new ways of manage competing demands on our freshwater resources.”
Humans use about 4,600 cubic km of water every year, of which 70% goes to agriculture, 20% to industry, and 10% to households, says the report, which was launched at the start of the triennial World Water Forum. Global demand has increased six-fold over the past 100 years, and continues to grow at the rate of 1% each year.
This is already creating strains that will grow by 2050, when the world population is forecast to reach between 9.4 billion and 10.2 billion (up from 7.7 billion today), with two in every three-people living in cities.
Drought and soil degradation are already the biggest risk of natural disaster, say the authors. The challenge has been most apparent this year in Cape Town, where residents face severe restrictions as the result of a once-in-384-year drought. In Brasília, the host of the forum, close to 2 million people have their taps turned off once in every five days due to an unusually protracted dry period.
The key for change will be agriculture, the biggest source of water consumption and pollution. The report calls for “conservation agriculture”, which would make greater use of rainwater rather than irrigation, and regularise crop rotation to maintain soil cover. This would also be crucial to reverse erosion and degradation, which currently affect a third of the planet’s land, a different UN study found last year.
Perhaps the most positive message of the report is that the potential savings of such practices exceed the projected increase in global demand for water, which would ease the dangers of conflict, provide better livelihoods for farming families, and reduce poverty.
By 2050, the report predicts, between 4.8 billion and 5.7 billion people will live in areas that are water-scarce for at least one month each year, up from 3.6 billion today; while the number of people at risk of floods will increase to 1.6 billion from 1.2 billion. Demand for water is projected to rise fastest in developing countries like Guyana.
Meanwhile, climate change will put an added stress on supplies because it will make wet regions wetter and dry regions drier. As the dry season approaches here, local authorities have already issued public advisories for residents to conserve water, and to monitor their water consumption.
