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Resilient Cities Blog

Earth Hour 2021

By Kirstin Johansen (Group Chair) and Sophie Sibley (Group Secretary)

Firstly, what is Earth Hour? On the last Saturday of March people across the word at 8:30pm (local time) will join in switching off their lights to show support for the planet.

It was originally started by WWF and partners, every year this event has grown and now engages 180 countries and territories worldwide. Earth Hour looks to increase awareness and instigate conversations about protecting nature, as once it’s gone it’s very hard to get it back. 

WWF have reported that if you were to add up all the benefits of nature to humans, farming, forestry, leisure and tourism etc, the benefits to humans is a minimum of US$125 trillion every year.

Joining together is a symbolic lights-out event, however even if you can’t join at 8:30, any hour (or more) of powder down can make a big difference.

In that time of lights out, it may be tempting to watch TV, play on the computer or find another activity that consumes electricity. Berners-Lee (2010), outlines the CO2e damages of our day to day activities. A unit of electricity from the UK grid equates to 600g CO2e, sitting playing on your laptop can cause 12g CO2e per hour and an old desktop machine 150g CO2e per hour. Moving on to watching TV, a 15-inch LCD flat screen can generate 34g CO2e per hours watching, a 28-inch CRT TV 76g CO2e per hour and a 42-inch plasma screen can generate 220g CO2e per hour. This Earth Hour might be time to pull out an old boardgame or book and read by candlelight (making sure to stay safe as calling out the fire engine could cause upwards of 2240g CO2e)

There are lots of other ways to reduce your climate impact, and only a few are detailed here. In your Earth Hour you could:

  • Plan a staycation instead of a vacation.
  • Write to your local politician asking for more climate friendly initiatives.
  • Plan a low carbon route to work.
  • Plan ‘Meat-Free’ Mondays or a Plant-Based food week (or go plant-based all together).
  • Make your own soap/body wash.
  • Separate your waste (recycling, general and food waste – if not more), and if your local council doesn’t have food waste write them asking for a food waste bin.
  • Repurpose old clothes (maybe a patchwork quilt, or tote bags for shopping).
  • Prep your meals for the week.
  • Upcycle old furniture.
  • Plan a 30 day zero-waste or no-plastic challenge.

(Wynes, 2019; Dyer, 2018)

Buildings also have many aspects that can be considered to help them become more sustainable and energy efficient (only a few are talked about here). With summer on its way it is important to consider solar gains. Heat from the sun can cause substantial overheating, this usually exacerbated by lots of glass, resulting in tenants feeling discomfort and using additional energy to combat the heat. Shading can help reduce this, closing the blinds at peak sunny hours; in addition, applying a reflective material on the building fabric and windows can also reduce heat gain. And insultation, while helpful in the winter, can minimise secondary problems from solar gain.

Your building water usage can often be forgotten about, but there are many products on the market now that can help you track your water usage. Products that can be fitted to help reduce water consumption, such as flow restrictors, or tap inserts. You can go one step further and install a Grey-water recycling system or install a water butt - using that for the garden instead of the hose. 

Looking at the lights you use, making sure they are always off when not in a room, and making sure they are the most energy efficient with a long life. If the bulbs keep dying and you have to replace them, not only is it annoying but you have that added carbon of all the bulbs being produced.
(Graham-Rowe, 2010; ShadeIT, 2021)

It is easy is to overlook buildings with all that is going on in the world in terms of the environment, but buildings can be a huge energy pit. This earth hour may be a chance to go round your house, flat, bungalow, or wherever your residence is and look for all areas you didn’t realise energy was being lost (for example under the front door).

Information mentioned above can be found in the below links.

International, W., 2021. Our Mission | Earth Hour 2021. [online] Available at: <> [Accessed 23 March 2021].
WWF, 2021. Valuing nature. [online] WWF. Available at: <> [Accessed 23 March 2021].
Berners-Lee, M., 2010. How Bad are Bananas?. London: Profile Books.
Wynes, S., 2019. SOS What you can do to reduce climate change. London: Ebury Press Penguin Random UK.
Dyer, H., 2018. Say no to plastic - 101 Easy Ways to Use Less Plastic. Chichester: Summersdale Publishers Ltd.
Graham-Rowe, D., 2010. How to make buildings more energy efficient. [online] the Guardian. Available at: <> [Accessed 25 March 2021].
ShadeIT, 2021. Reducing Solar Gain - ShadeIT. [online] ShadeIT. Available at: <> [Accessed 25 March 2021].


World Environment Day 2020

Urban Biodiversity – The Need For Green Growth

Kirstin Johansen

5th June 2020

The loss of biodiversity, together with the changing climate forms an existential planet emergency.  Both for the world’s cities and economies.

At the 2020 World Economic Forum – nature was top of the agenda.  The precedence of this was set when the Intergovernmental Panel on Biodiversity and Ecosystems report claimed upto one million species face extinction by 2050.

Biodiversity needs to be fostered significantly more within the world’s cities.  Over half of the population live within cities and it is important to understand the integration of humans and cities - it is our collective responsibility to ensure we include not only pleasant green and blue spaces, but living urban nature to include habitats for wild species.

Urban Design

The benefits of biodiversity within cities is profound.  Current urban planning approaches typically consider biodiversity a constraint – a “problem” to be dealt with. At best, biodiversity in urban areas is “offset”, often far from the site of impact.

This is a poor solution because it fails to provide nature in the places where people can benefit most from interacting with it. It also delivers questionable ecological outcomes.

Biodiversity-sensitive urban design (BSUD) aims to create urban environments that make a positive onsite contribution to biodiversity. This involves careful planning and innovative design and architecture. BSUD seeks to build nature into the urban fabric by linking urban planning and design to the basic needs and survival of native plants and animals.

Abrupt Biodiversity Loss and Climate Change

Projections from studies indicate a sharp and sudden loss of biodiversity unless emissions are quickly reduced, upto 50% of species are expected to lose a majority of optimum climate conditions by 2100 and sudden biodiversity loss could occur sooner than expected; ecosystems will be facing a sharp cliff edge as opposed to a climate change slope.

An abrupt loss of biodiversity poses a very significant threat to human well-being.  In a vast number of countries, reliance for food security and income is heavily resourced from their immediate natural environment.  Abrupt disruption to this will affect their income and food consumption, potentially forcing poverty.

Multi Benefits of Biodiversity

The ecological crisis requires radical change, a re-design of the way we live and in the way our societies are organised.  City nature can strengthen local, national and global diversity.

Greening has a calming and healing effect enhancing human health and well-being. Evidence suggests numerous health benefits to include social and psychological; stress & anxiety reduction and overall greater physical and mental wellbeing.   

Shinrin-yoku or “forest bathing” is practiced in Japan as preventative healthcare, we are happiest when surrounded by nature which may be due to the evolution of our biophilia co-evolving over the millions of years from human and plant contact.

Plants contribute to cleaner air, reducing harmful pollutants and microscopic matter through complex processes.  Unlike parks, urban nature is a living ecosystem.  Organisms live and reproduce.

Green areas create cool areas and natural shade, improving city microclimates.  Green roofs and walls can provide habitats for wildlife and reduce the impact of the urban heat island, as well as absorbing rainwater and improving building insulation.  Greening our cities reverses the steady erosion of the rich earth, and allows social connection and happiness in the process.

Due to urbanisation, plant sales have boomed, it’s seen as a relief from the over developed cities we live in.  People want and desire nature.
Biodiversity and Recent Climates

The last few months have been one of significant interest to climate researchers globally.  Within the duration of the Covid-19 pandemic, factories closed, forms of travel became a thing of the past – trains, flights, car traffic all significantly reduced.  Entire industries were shut down.

City air pollution around the world dramatically decreased, water quality across large cities vastly increased, over fishing had been depleting fish biomass - this is returning.  Sea turtles are returning to areas they once lay their eggs. 

The air is cleaner, the water is clearer, plants are thriving.

As Covid-19 recovery takes economic impact, will open space management take the hit.  Easy cuts could potentially have devastating effects on planting diversity and in turn this will effect insects and entire urban ecosystems.  There are also inequalities to consider.  Access to green space isn’t universal and can further drive inequality within society.  Studies have shown links between income inequality, green space access and life expectancy.
Towards a Thriving Future

The greening of our cities is happening in many urban spaces globally.  Sadiq Khan has aspirations to make London a “National Park City” rewilding more than half of the capital by 2050.  With a collaborative approach between professional working groups the integration of biodiversity within our cities will help achieve this. 

The impact of professions such as engineers, architects, planners and surveyors, to name but a few, have on protecting and enhancing biodiversity is enormous.  Decisions in relation to roofs, walls, construction materials, the assembly, their disposal and a building’s air & water pollution are all paramount.

The adverse effects of a building on the surrounding environment is in the hands of the professional teams and the protection of biodiversiy for those reasons aforementioned should be pivotal in decision making.
As stated by the United Nations keeping nature and species diversity intact will also protect us against pandemics.  We need to appreciate the vital role of the health of our planet and take immediate action to conserve eco-systems.

We have been sent an important message by nature.  This positive impact needs to remain globally and across the world’s cities, and together we can contribute towards achieving this.
Reference and Further Reading: