Climate change threats including storms, rising sea levels and flooding have stimulated the dredging industry to find new sustainable solutions.
The scientific community has confirmed that the Earth's climate is changing. Climate events are becoming more extreme with higher temperatures and changing precipitation (snow and rain) rates and patterns. Some of these extremes have been linked to the increasing levels of CO2 and other greenhouse gases caused by human activities.
Dredging & climate change
Dredging operations have both positive and negative effects as regards climate change. All maritime activities, including dredging vessels, emit gases into the atmosphere; these emissions add to the problem of global warming. International treaties from the United Nations’ International Maritime Organization have set goals for reducing emissions from maritime activities. The European Union has adopted these standards as being the most effective. The United States Environmental Protection Agency is also pro-active in limiting fuel emissions.
The aim is to reduce the use of fuels that emit gases which add to the rise in temperatures and thus are detrimental to controlling climate changes. The dredging industry and those who supply ships and engines to the industry have been actively seeking new technologies to meet these IMO standards.
Dredging to mitigate damages from climate change
While climate change can be impacted negatively by gas emissions, dredging can also provide positive, sustainable solutions to mitigate the potential damage caused by rising sea levels and the increase in extreme weather.
Dredging occurs along coastlines, ports and access channels, rivers, lakes and estuaries. All these areas are affected by rising sea levels and increases in storms which can create life- and property-threatening floods. Dredging can help adapt to the threats of these conditions by offering preventative measures such as:
- maintaining the safety of navigation at ports and access channels;
- constructing infrastructure that manages coastal flood and erosion risks, e.g., higher or stronger embankments or dunes and deeper channels and rivers;
- managing and adapting wetland and habitat adaptations;
- enlarging water storage capacity (reservoirs, lakes) to meet increases in precipitation;
- regulating sedimentation, also in some cases, of contaminated soils from agriculture or urbanisation.
The 'With Nature' movements
The dredging industry has actively been pursuing wide variety of sustainable solutions to climate change. To facilitate the implementation of these solutions, the industry bears a responsibility to engage nearby communities to understand the long-term benefits of dredging projects.
Building with Nature (Ecoshape), Working with Nature (PIANC) or Engineering with Nature (US Army Corps) are all systems which utilise the dynamics of nature and ecosystems as the jumping off point to design a dredging project. These are targeted tools for sustainable solutions that take into account climate change issues from the start.
Blue carbon sequestration
Coastal ecosystems, such as mangroves, tidal marshes, and seagrass meadows and so on, sequester and store significant amounts of coastal blue carbon from the atmosphere and oceans and thus contribute to mitigating climate change. These ecosystems provide protection from rising sea levels and severe storms. They prevent shoreline erosion and help regulate coastal water quality. They provide security for coastal communities as well as for commercial fisheries and protect habitats of endangered marine species.
Numerous projects and pilot projects have been and are being conducted to prepare for climate change and its related challenges such as sea level rise and flooding. Also research involving sequestration of carbon and reduction of the carbon footprint of a project are ongoing in the hope to reduce or reverse the causes of climate change.