An estimated six billion tonnes of sand are being dug up from the ocean every year.

What’s happening? Marine Sand Watch uses AI to track the movement of dredgers from automatic identification systems (IAS) data provided by Global Fishing Watch. It found the east coast of the US, the North Sea and Southeast Asia were areas of concern. In several locations where dredging is particularly intense, sand is often being removed faster than it can be naturally replenished.

Why does this matter? Sand stands as the second most utilised natural resource globally, trailing only behind water. Each year, approximately 50 billion tonnes of sand and gravel are consumed – a quantity substantial enough to construct a wall measuring 27 meters in height and 27 meters in width, encircling the entire Earth.

Sand assumes a pivotal role in our daily lives and economic progress, serving as an indispensable ingredient in the production of concrete, asphalt, glass, silicon chips, and playing vital roles in land reclamation and flood protection efforts. Furthermore, it plays a crucial role in facilitating the construction of the extensive infrastructure necessary for the transition to cleaner energy sources.

Limited supply – UNEP’s data spanning from 2012 to 2019 reveals a concerning trend: dredging activities are on the rise. Every year, coastal and marine ecosystems depend on an essential influx of 10 to 16 billion tonnes of sand from the land.

Currently, global sand dredging is approaching this critical replenishment rate. Predictions indicate that factors such as the expanding global population, urbanisation, poverty reduction efforts, and the increasing demand for new infrastructure like roads and buildings will necessitate an astonishing 60 billion tonnes of sand and gravel per annum by 2030.

Focusing on the construction sector specifically, estimates suggest that the demand for construction-grade sand will surge from 3.2 billion tonnes in 2020 to 4.6 billion tonnes by 2060, marking a substantial 45% increase.

According to a 2022 UNEP report, it’s important to recognise that global sand reserves remain largely unknown, and assuming the resource’s abundant availability would be a mistake. Shortages are presently emerging due to disparities in the geographical distribution of resources, as well as variations in quantity and quality at regional sites, creating a substantial threat to supply chains.

Furthermore, there’s a rising competition for extraction sites, and numerous regions are implementing restrictions, often in the name of nature conservation, further complicating the situation.

Threat to marine life – Extracting sand not only strains the global supply but also leaves areas of the seabed “sterilised” through the removal of microorganisms vital to marine ecosystems. In some cases where sand is stripped down to the bedrock “life may never recover”, according to UNEP’s Pascal Peduzzi. Dredging affects marine wildlife in various other ways including collisions, noise levels and topology.

Lack of regulation – UNEP highlight that sand extraction is unregulated or under-regulated in many parts of the world. Just a handful of countries know how much sand is being extracted each year, what it is used for and how it impacts the environment or socio-economic issues.

In addition to limited legislation, a lack of data can drive illegal, informal, and unregulated sand mining, which harms the environment and negatively impacts society.

Industries harmed – Excessive sand extraction also threatens local industries. For example, UNEP emphasises that removing sand from beaches can inhibit the development of tourism, which is integral to both local and national economies.

Additionally, mining sand from rivers can result in the loss of livelihoods, including tourism and fishing. An example of this can be seen on the riverbanks along the Mekong and Bassac rivers in Cambodia, which have been collapsing, forcing residents to leave their homes.

Solutions – UNEP has called for new legislation to more effectively govern sand and for resources of the material to be mapped, monitored and reported on. Solutions already exist, such as creating a circular sand economy, including banning the resource from landfills and encouraging reuse in public procurement contracts.

Recycling construction and demolition materials are also potential alternatives to sand, as is ore-sand resulting from the mining and processing of ores.

Source: The Guardian 

Greenland’s ice sheet is likely to disappear regardless of how quickly greenhouse gas emissions are reduced, with annual snowfall insufficient to replenish the snow and ice lost during summer melting, according to a study from Ohio State University. The research was based on 234 Arctic glaciers during the 34 years to 2018. The loss of all of Greenland’s ice would raise sea levels by six metres, causing many coastal cities to flood. The Arctic has been warming at twice the rate of the rest of the world for the last 30 years.

The Ohio study investigates the Greenland ice sheet’s mass balance – the net of mass gained by snow accumulation in its interior and lost from ice melting at its edges – which was stable in the 1990s but has been falling since, and at an increasing pace.

It finds Greenland’s outlet glaciers are speeding up due to increased “calving” – where ice breaks off glacier termini. The authors state that glacier retreat in the early 2000s switched the ice sheet to operate in a new dynamic, where its shrinkage will be sustained even if temperatures stabilise. This could result in a sea level rise of over six metres by the year 3000.

A separate study published this month uses satellite measurements to estimate the ice sheet lost one million mt of ice per minute across 2019, totalling 532 billion mt, which is double the average rate post-2003. The authors suspect 2019’s loss – the largest in centuries, and potentially millennia – is due to changing atmospheric dynamics that hold warmer air over the ice sheet. These are themselves the result of climate change.

Looking more broadly, a further academic review of all land-based ice has found the Earth’s surface has lost 28 trillion mt of ice since 1994. This rate, which will result in a metre of sea level rise by 2100, is tracking the Intergovernmental Panel on Climate Change’s worst-case scenario for ice loss.

Sources:

Nature Communications Earth and Environment

Reuters

https://uk.reuters.com/article/us-climate-change-arctic/canary-in-the-coal-mine-greenland-ice-has-shrunk-beyond-return-study-finds-idUKKCN25A2X3