by Vincent Diringer
As the climate crisis begins to take a more important position amidst international politics, the need for strong mitigation has been echoed by calls for a rapid transition towards a low-carbon future – but what exactly does that mean? Even prior to the first Intergovernmental Panel on Climate Change report was published in 1989, scientists had been advocating for the inclusion of renewable energy .
The debate around carbon emissions, the damage they cause, their sources, and how best to transition away from them has dominated media conversations since the ratification of the Paris Agreement in 2015. Among the throng of information and political spin presented regarding the answers to the above, it is easy to find yourself lost as to what is actually being done to control global emissions. The short and easy of it is simple: we are well short of the emissions reduction targets set out at COP21 .
There is no denying that policy – both domestic and international – is a slow difficult process, but the need for action is more pressing than ever. The tools capable of ensuring a low-carbon future are as diverse as the reasons that have held up their wide-spread implementation, but without delving into the politics, here are the options that we currently have before us.
Responsible for 73.2% of global greenhouse gas emissions in 2016, energy (transport; industrial, commercial, and residential power usage) has long been earmarked as one of the sectors most in need of an overhaul . Finding low-carbon energy sources to power our electrical grids is not as difficult as it may seem. Renewables such as solar, wind, geothermal, hydroelectric, ocean, and bioenergy are all accepted alternatives that see usage in different power grids globally.
A popular form of renewable energy, solar power makes the most of the Sun’s daily cycle through the use of photovoltaic panels that capture sunlight. A relatively cheap option that can be installed on an individual or industrial level, solar panels are one of the most prevalent forms of low-carbon energy on the market. The International Energy Agency (IEA) expects global installed solar capacity to expand by 50% by 2024, thanks mostly to government commitments to reduce carbon emissions and an increasingly competitive energy market .
One of the oldest forms of renewable energy, hydropower has a significant role in many countries’ electrical grids. Sourced mainly through natural freshwater waterways via dams that control water release rates downstream through a generator, hydroelectricity has the largest share of low-carbon renewable energy on a global level. Costa Rica notably runs an energy grid which features close to 100% renewable power, with hydro contributing 65% of total production to it . Outside of dams, hydro also encompasses ocean-based energy sources, but while the use of tidal or wave-power is not widespread there is hope it could increase in coming years.
Another recognizable source of renewable energy, wind power provides very cost-efficient power generation. Able to be deployed at sea or on land, it provides utility companies with a wide range of opportunities to capitalize on local wind patterns. Along with solar, wind has gained popularity across the world as a cheap, easy and efficient power source and is expected to have a major role in the transition away from fossil fuels. The International Renewable Energy Agency (IRENA) projects global wind power capacity to rise from 600MW to close to 1800MW by 2030  .
By harvesting the Earth’s internal temperature through a series of deep pumps, geothermal power provides close to 15,000MW of energy to countries around the world . The infrastructure needed to use geothermal energy is more complex than those outlined above, but it remains a strong renewable energy source that could also see a rise in popularity as countries seek to diversify their energy portfolios. Seen as a perfect complement to intermittent renewables such as solar and wind, installed geothermal capacity could expand by a factor of eight in Europe alone .
Touted as one of the more interesting and versatile forms of renewable energy on the market, bioenergy uses biological materials to provide power. Including but not limited to agriculture-based options, food waste or the sustainable use of wood and other resources, bioenergy has a range of sources. Whether processed to become liquid biofuels or physical fuel, it has been used in transport and energy grids at both an individual and commercial level. It currently makes up 130MW of global energy production, but is seen as a key energy source for developing nations  .
Renewables in and of themselves are able to help nations capitalize on their local environment. Their ability to use natural resources without exhausting them ensures sustainability is passed directly down to the consumers through cheaper rates and low-emissions impact unit lifespans – yes, including the manufacturing and implementation of these methods. While there has been growing debate as to the total carbon cost of implementing these energy sources, it pays to remember that most of the other options available are fossil fuels, which are a much higher net-positive carbon emitter. However there remain two more energy options that can be counted towards low-carbon power solutions.
Gaining traction as an alternative source of power, hydrogen has long been seen as the energy of the future. Created by splitting water into its base parts – hydrogen and oxygen – it has the potential to become a game-changer in terms of how we produce energy. However, while much progress has been made to create hydrogen-based transports and find ways of implementing into the power grid, hydrogen can only be truly deemed a renewable energy source if the energy used to create it is from a renewable source . As global grids still heavily rely on fossil fuels, there are not many options for low-carbon hydrogen – but that could soon change .
Despite a poor reputation, nuclear remains one of the strongest options for a transition towards a low-carbon future . Capable of providing a high baseload of energy that can only be matched by hydroelectric and fossil fuel, nuclear has the capacity to replace coal furnaces en masse without creating a dip in production. While posing its own disadvantages in terms of nuclear waste and the carbon emitted through their lengthy construction periods, nuclear provides an opportunity for a stable transition while renewable energy capacity increases to eventually phase out the need for reactors .
This concludes the first article of a multi-part series breaking down the current pathways to a low-carbon future. Stay tuned for more information regarding technology, transport and society.