Modern Australian
Men's Weekly

.

how much of the world's energy comes from fossil fuels and could we replace it all with renewables?

  • Written by Robert McLachlan, Professor in Applied Mathematics, Massey University
how much of the world's energy comes from fossil fuels and could we replace it all with renewables? CC BY-ND Climate explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change. If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz How are fossil fuels formed, why do they release carbon dioxide and how much of the world’s energy do they provide? And what are the renewable energy sources that could replace fossil fuels? Fossil fuels were formed over millions of years from the remains of plants and animals trapped in sediments and then transformed by heat and pressure. Most coal was formed in the Carboniferous Period (360–300 million years ago), an age of amphibians and vast swampy forests. Fossilisation of trees moved enormous amounts of carbon from the air to underground, leading to a decline in atmospheric carbon dioxide (CO₂) levels — enough to bring the Earth close to a completely frozen state. This change in the climate, combined with the evolution of fungi that could digest dead wood and release its carbon back into the air, brought the coal-forming period to an end. Oil and natural gas (methane, CH₄) were formed similarly, not from trees but from ocean plankton, and over a longer period. New Zealand’s Maui oil field is relatively young, dating from the Eocene, some 50 million years ago. Read more: Climate explained: why carbon dioxide has such outsized influence on Earth's climate Burning buried sunshine When fossil fuels are burnt, their carbon reacts with oxygen to form carbon dioxide. The energy originally provided by the Sun, stored in chemical bonds for millions of years, is released and the carbon returns to the air. A simple example is the burning of natural gas: one molecule of methane and two of oxygen combine to produce carbon dioxide and water. CH₄ + 2 O₂ → CO₂ + 2 H₂O Burning a kilogram of natural gas releases 15kWh of energy in the form of infrared radiation (radiant heat). This is a sizeable amount. To stop continuously worsening climate change, we need to stop burning fossil fuels for energy. That’s a tall order, because fossil fuels provide 84% of all the energy used by human civilisation. (New Zealand is less reliant on fossil fuels, at 65%.) Wind turbines on farm land in New Zealand Wind energy is one of the renewable sources with the capacity to scale up. Shutterstock/YIUCHEUNG There are many possible sources of renewable or low-carbon energy: nuclear, hydropower, wind, solar, geothermal, biomass (burning plants for energy) and biofuel (making liquid or gaseous fuels out of plants). A handful of tidal power stations are in operation, and experiments are under way with wave and ocean current generation. But, among these, the only two with the capacity to scale up to the staggering amount of energy we use are wind and solar. Despite impressive growth (doubling in less than five years), wind provides only 2.2% of all energy, and solar 1.1%. The renewables transition One saving grace, which suggests a complete transformation to renewable energy may be possible, is that a lot of the energy from fossil fuels is wasted. First, extraction, refining and transport of fossil fuels accounts for 12% of all energy use. Second, fossil fuels are often burnt in very inefficient ways, for example in internal combustion engines in cars. A world based on renewable energy would need half as much energy in the first place. The potential solar and wind resource is enormous, and costs have fallen rapidly. Some have argued we could transition to fully renewable energy, including transmission lines and energy storage as well as fully synthetic liquid fuels, by 2050. One scenario sees New Zealand building 20GW of solar and 9GW of wind power. That’s not unreasonable — Australia has built that much in five years. We should hurry. Renewable power plants take time to build and industries take time to scale up. Other factors to consider Switching to renewable energy solves the problems of fuel and climate change, but not those of escalating resource use. Building a whole new energy system takes a lot of material, some of it rare and difficult to extract. Unlike burnt fuel, metal can be recycled, but that won’t help while building a new system for the first time. Research concluded that although some metals are scarce (particularly cobalt, cadmium, nickel, gold and silver), “a fully renewable energy system is unlikely to deplete metal reserves and resources up to 2050”. There are also opportunities to substitute more common materials, at some loss of efficiency. Engineers working on a wind turbine Building a new system will require energy and resources. Shutterstock/Jacques Tarnero But many metals are highly localised. Half the world’s cobalt reserves are in the Democratic Republic of Congo, half the lithium is in Chile, and 70% of rare earths, used in wind turbines and electric motors, are in China. Wasteful consumption is another issue. New technologies (robots, drones, internet) and economic growth lead to increased use of energy and resources. Rich people use a disproportionate amount of energy and model excessive consumption and waste others aspire to, including the emerging rich in developing countries. Read more: Renewable energy can save the natural world – but if we're not careful, it will also hurt it Research analysing household-level emissions across European countries found the top 1% of the population with the highest carbon footprints produced 55 tonnes of CO₂-equivalent emissions each, compared to a European median of 10 tonnes. Scientists have warned about consumption by the affluent and there is vigorous debate about how to reduce it while preserving a stable society. One way of turning these questions around is to start from the bottom and ask: what is the minimum energy required for basic human needs? One study considered “decent living” to include comfortable housing, enough food and water, 10,000km of travel a year, education, healthcare and telecommunications for everyone on Earth — clearly not something we have managed to achieve so far. It found this would need about 4,000kWh of energy per person per year, less than a tenth of what New Zealanders currently use, and an amount easily supplied by renewable energy. All that carbon under the ground was energy ripe for the picking. We picked it. But now it is time to stop.

Authors: Robert McLachlan, Professor in Applied Mathematics, Massey University

Read more https://theconversation.com/climate-explained-how-much-of-the-worlds-energy-comes-from-fossil-fuels-and-could-we-replace-it-all-with-renewables-167190

7 Common Air Conditioner Issues in Melbourne – And How to Fix Them

Image by freepik Living in Melbourne, we all know how unpredictable the weather can be. One moment it’s cold and windy, the next it’s a scorchin...

Powering Palm QLD with Reliable Electrical Solutions

Image by pvproductions on Freepik When it comes to finding a trustworthy electrician Palm QLD locals can count on, the team at East Coast Sparkies s...

The Smart Way to Grow Online: SEO Management Sydney Businesses Can Rely On

If you’re a Sydney-based business owner, you already know the digital space is crowded. But with the right strategy, you don’t need to shout the...

What Your Car Says About You: The Personality Behind the Vehicle

You can tell a lot about someone by the car they drive—or at least, that’s what people think. True Blue Mobile Mechanics reckon the car says a l...

The Confidence Curve: Why Boudoir Photography Is the Empowerment Trend You Didn’t Know You Needed

Boudoir photography has been quietly taking over social feeds, Pinterest boards, and personal milestones—and for good reason. It’s not just abou...

Understanding Level 2 Electricians: Why Sydney Residents Need Licenced Experts for Complex Electrical Work

When it comes to electrical work around the home or business, not all electricians are created equal. In Sydney, particularly when you're dealing wi...

Retirement Anchored in Model Boat Building for Waterford’s Doug Unsold

WATERFORD — When Doug Unsold sees his ship come in, it’s usually one he’s crafted with his own hands. The 67-year-old retiree from Waterford ...

The Science Behind Alarm Clocks and Your Circadian Rhythm

Waking up on time isn’t just about setting an alarm—it’s about working with your body, not against it. At the heart of every restful night and...

How to Use Plants to Create a Calming Atmosphere in Your Home

In today’s fast-paced world, cultivating a calm, soothing environment at home has never been more important. Whether you live in a busy urban apar...

How Maths Tutoring Can Help Students Master Maths

Mathematics can be a daunting subject for many students, often causing stress and frustration. However, maths tutoring has proven to be an effective...

Refurbished iPads Are Better Than New Ones (Here's Why)

Image by rawpixel.com on Freepik Apple's refurbished iPad program has quietly become one of the best deals in tech. While everyone obsesses over the ...

Your Guide to Finding the Right GP: What Perth City Doctors Offer Today

Choosing a General Practitioner (GP) is one of the most important health decisions you’ll make. Luckily, Perth’s vibrant CBD now hosts a new ge...

Why Every Mining Operation Needs a Robust Safety Management System

Mining is one of the backbones of the Australian economy, particularly in Western Australia. Back in 2019-20, mining contributed 10.4% of Australia...

Australian Classic Literature Enjoys Resurgence

Welcome back to the good old days of storytelling! As the modern world becomes increasingly more demanding, returning to childhood favourites offers...

How to Choose the Right Lawyers in Sydney for Your Situation

When faced with a legal issue, selecting the right legal representation can make all the difference. Whether you're dealing with a personal injury, ...

Building a Governance Model for Headless Content Management at Scale

Image by pch.vector on Freepik There's never been a better time to implement a headless content management system (CMS) to gain the flexibility and ...

Understanding Trade Insurance: Essential Protection for Businesses

Image by Drazen Zigic on Freepik In the current economic environment, trade insurance is an important element for companies trading both locally an...

Choosing the Right Timber for External Cladding

Timber cladding is one of those finishes that pulls double duty: it makes a building look warm and welcoming, and it quietly shields the frame from ...