Climate and ecology

We are in the midst of a global climate and ecological emergency unprecedented in human history.

We believe that there is still an opportunity to mitigate against this crisis and that the Horniman has a moral and ethical imperative to act now.

Our Climate and Ecology Manifesto outlines the steps we will take to mitigate against the climate and ecological emergency, to help shape a positive future for generations to come. Our pledges include the intention to be greenhouse gas neutral by 2040.

Read our manifesto:

Our 2022/23 impact 

Our carbon footprint was 506 tonnes of CO2e*. This is equivalent to the heating and electricity used by 153 households for 1 year on average.

  • 99.9% food and garden waste composted (14.90T)
  • 32.6% daily waste recycled (23.33T)
  • 43,462 kWh/year electrical saving from upgrading Aquarium pumps and reconfiguring filtration
  • Five contributions to scientific publications by Aquarium staff
  • 1,700+ Environment Champions Community subscribers
  • 100+ members of staff completed Carbon Literacy Training
  • 9,863 children engaged in workshops about the environment/sciences
  • 1,068 children engaged in outdoor learning sessions
  • 80% agree that visiting increased their curiosity about the natural world
  • 82% agree that visiting has made them appreciate the natural world more

*CO2e.(carbon dioxide equivalent) includes all four greenhouse gases, although our emissions are primarily CO2, including:

  • direct emissions (scope 1) from on-site use of energy (gas),
  • indirect emissions (scope 2) from purchased energy (electricity),
  • and emissions resulting from business travel and waste (scope 3).

Our scope 3 calculation does not currently include visitor travel and other indirect emissions e.g. from suppliers.

Work in progress

  • We have begun work on our Nature + Love project, thanks to funding from National Lottery Heritage Fund. Over the next two years we will be redeveloping and improving access to two areas of the Gardens and the Natural History Gallery – with love for the natural world at the heart of the project.
  • We are currently working on saving and reusing water in our Aquarium and across the Gardens.
  • We will continue to promote active travel to our visitors, alongside encouraging them to Ditch the Drive and choose public transport over cars.
  • We are expecting a report soon on the work and costs involved in retrofitting the main museum building, to reduce its carbon footprint.


  • A cross-departmental Climate and Ecology Action Group drives our work towards our manifesto goals, and champions environmental issues across the Horniman.
  • Our staff are all taking part in Carbon Literacy Training, which includes making pledges to take a personal and a work-based action to reduce your carbon footprint.
  • Our Environment Champions Community (ECC) encourages communities and families to adopt more environmentally friendly behaviours.
  • 40 dedicated and enthusiastic people from our local community are Gardens volunteers, giving their time to help us with a variety of initiatives in the Gardens.
  • We are a Green Flag venue and part of the Green Chain Walk, and our Gardens are regularly visited by the Lewisham Healthy Walks group.
  • Our electricity is from guaranteed renewable sources and all the bulbs in our Aquarium display tanks are LEDs, saving over 11,000 KWh per year of electricity (the equivalent of boiling 100,000 kettles).
  • Almost half of our total waste (around 48%) is now recycled, including composting; only around 1% of waste ends up in landfill; the rest is incinerated to create energy.
  • Our cleaning products are environmentally considerate ones, which we buy in bulk to reduce plastic packaging. We use reusable, washable cleaning cloths and have reduced paper usage and waste by updating our dispensers for toilet paper and paper towels.
  • Our 茶, चाय, Tea (Chá, Chai, Tea) exhibition explores the many stories of Britain’s national drink, spanning millennia and connecting communities across the world. One section of the exhibition looks at sustainability in tea production – and the exhibition design reflects this, using repurposed and recyclable materials, wherever possible.
  • In 2023, our Matters of Life and Breath display focused on a cornet belonging to Ella Roberta Adoo Kissi Debrah, the young girl from Lewisham who was the first person in the world to have air pollution listed on her death certificate. The display marked the progress through Parliament of the historic Clean Air Bill, also called Ella’s Law, which establishes the human right to breathe clean air.
  • We worked with our Youth Panel on the Sustainable Way display in our World Gallery, which raises awareness of the environmental impact of the cotton industry, inspired by the Hopi people and their respectful and sustainable farming of the land.
  • In summer 2023 the Horniman Gardens displayed five art boards featuring work from local children, as part of The Wild Escape, a UK-wide creative project for museums and schools led by Art Fund. The artworks were inspired by the Horniman’s Natural History collection and explored creatures, their habitats and the threats posed by the climate crisis.

Our Gardens and Nature Trail are a haven for wildlife.

  • We have birdhouses, bat boxes and bug hotels, and our award-winning Bee Garden provides habitats and food sources for multiple bee species.
  • Thousands of flowering bulbs supply food for early pollinators as well as some colour for us to enjoy in late winter and spring.
  • Reduced mowing in some areas reduces our fuel emissions, and in some areas we don’t mow – leaving the grass to grow long creates a safe haven for insects and encourages indigenous wildflowers.
  • Our densely planted micro-forest is growing quickly and will create a ‘green screen’, absorbing CO2 and air pollution from traffic on the South Circular, blocking noise pollution and providing additional habitats for wildlife.

We are making changes around the Gardens to plant in a more climate-aware and ecologically friendly way.

  • The deeper pond and its ramp in the Sunken Garden allow us to grow more water plants and sustain more wildlife species, and we’re moving to longer-lasting planting around the pond, which benefits soil health and wildlife.
  • In beds alongside the Butterfly House and close to the Clocktower, we’re using plants from around the world, chosen for their drought tolerance and resistance to warmer temperatures caused by climate change.
  • The weekly Horniman Market sells products direct from independent and local producers including seasonal fruit and veg, and organic meat, plus stalls specialising in zero waste, ethical crafts and eco clothing and design. See the current stallholders.
  • Our quarterly Second-hand Sundays have a repurposing, reusing and recycling focus and run alongside the regular Horniman Market.
  • Our shops no longer offer single-use bags for customers’ purchases, and we have reviewed and reduced our ‘pocket money’ products. The shops stock a number of fair-trade items, as well as working with UK artisans and makers to create unique products inspired by the Horniman’s collections.