I spend a lot of time at engineering, innovation and sustainability events. The venues change. Sometimes it is a university lecture theatre. Sometimes it is a startup demo day. Occasionally it is a factory floor where everyone is wearing high-visibility jackets and nodding seriously at a machine that has been running perfectly well for years.
What does not change... are the questions.
Once the panel ends or the coffee arrives, someone inevitably asks me a version of the same thing.
- What do you actually mean by climate tech?
- Is clean tech the same thing as green tech?
- And where do deep tech and artificial intelligence fit into all of this?
These are not naive questions. They are sensible ones. The fact that so many engineers ask them suggests we have a language problem, not a capability problem.
The misconception that keeps coming up
When I started in this industry, I was under a common assumption that that these terms describe a hierarchy. As if green tech is the entry level, clean tech is more serious, climate tech is the main event, and deep tech is the most advanced version of all.
In reality, in essence, these labels describe different lenses on the same challenge, not levels of technical quality or moral virtue.
Climate change is not a single engineering problem. It spans energy systems, manufacturing, materials, transport, buildings, data and human behaviour. Different communities have developed different language to describe how they approach it.
The trouble starts when the simple labels replace the explanations.
What climate tech actually means
Climate technology refers to technologies whose primary purpose is to reduce greenhouse gas (GHG) emissions or help society adapt to climate change.
That includes software, hardware, infrastructure and services. Examples include energy optimisation platforms, grid balancing tools, carbon accounting systems and low-carbon materials.
A simple test is intent. If the climate benefit disappeared, would the solution still exist? If the answer is no, it is probably climate tech.
Where does clean tech fit in?
Clean tech is broader and older.
It focuses on reducing environmental harm overall, not only emissions. That includes pollution, waste, toxic materials and inefficient use of energy and resources.
Renewable energy systems, electric vehicles, water treatment technologies and efficient industrial processes all sit comfortably in clean tech.
Many solutions overlap with climate tech. That overlap is normal and often desirable.
And what about green tech?
Green tech is the broadest and least precise term.
It is often used as a public-facing label for products or services that claim an environmental benefit. Sometimes that includes robust climate or clean technologies. Sometimes it reflects intent, branding or early-stage ideas rather than measured outcomes.
Green tech is not inherently misleading, but the label alone tells engineers very little. It should be treated as a starting point for questions, not an answer in itself. There is overlap here too with the former mentioned terms, but some example of key developments can be membrane filtration, microbial fuel cells, nanotechnology, development of biological treatments, and so on.
NOW.. Deep tech and artificial intelligence, without the mystique
Deep tech does not describe what problem is being solved. It describes how difficult the technology is to build.
These solutions are rooted in advanced science or engineering and are harder to replicate quickly. Artificial intelligence, advanced materials, robotics and biotechnology are common examples.
Artificial intelligence in particular attracts attention. Used well, it can optimise complex systems, identify patterns and support decision-making at scale.
Used badly, it becomes an expensive way of rediscovering what experienced engineers already know.
Artificial intelligence is not a climate solution by default. It is a tool. Like most tools, it works best when applied to the right problem. (Let's not go into the discussion of water usage of using AI and running data centres; that is a discussion for another day!)
Psst.. how does the circular economy in all of this?
The circular economy is often discussed alongside these technologies, but it is not a technology at all.
It is a systems way of thinking.
Instead of the traditional take, make, dispose model, circular approaches aim to keep materials and value in use for as long as possible through reuse, repair, remanufacturing, recycling and better design.
This is where many climate, clean and green technologies either succeed or fail. Technology can support circularity, but it cannot replace systems thinking.
The challenges nobody puts on the slide deck
Across sectors, the same obstacles appear repeatedly.
Measurement is still difficult. Many organisations lack reliable operational data.
Incentives are often misaligned. Environmental benefits tend to arrive on longer timescales than financial ones, especially for small and medium-sized organisations.
And language itself becomes a barrier. When terminology becomes vague or overloaded, it excludes the people who actually have to make systems work.
How to spot real impact vs greenwashing via tech jargons
A practical checklist:
These are questions I find myself asking repeatedly, often while holding a lukewarm filter coffee (I know it's usually free, but I can still complain).
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Is the problem clearly defined?
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Is the mechanism for impact explained?
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Are data sources transparent?
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Are trade-offs acknowledged?
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Does it work within real-world constraints?
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Is the environmental benefit core to the solution?
A simple comparison everyone can actually use:
| Term | Primary focus | What it tells you | What it does not guarantee |
|---|---|---|---|
| Climate Tech | Emissions reduction or climate risk | Clear climate intent | Scalable or affordable impact |
| Clean Tech | Reducing environmental harm | Practical improvement | Direct carbon reduction |
| Green Tech | Claimed environmental benefit | Sustainability intent | Evidence or technical rigour |
| Deep Tech | Advanced science or engineering | Technical defensibility | Speed of adoption |
| Circular Economy | System and material flows | Long-term resource thinking | That technology alone will solve it |
Why any of this matters?
This is not a debate about terminology for its own sake. It is about making better decisions.
What problem is being solved. For whom. By what mechanism. At what cost and over what timeframe?
Engineering has always been about turning complexity into systems that work. The climate challenge simply raises the stakes.
- Which terms do you find most confusing?
- Where does circular economy thinking break down in practice?
- And where do you think engineers can make the biggest difference next?
I would love to hear your thoughts.