What’s stopping us from carrying on exactly as we are?

Hopefully by now we have all realised that there is a climate emergency. Global warming is accelerating at a pace the earth cannot sustain and the recently completed IPCC sixth assessment report stated that it is “now or never” for us to make changes that can really make a difference.

And, while the construction industry is starting to make changes that could help, we are not moving very quickly. Cost, programme and standard processes are all massive barriers to change. But does it really matter? What will actually happen if we don’t start making big changes?

Let’s imagine the situation between now and 2050 if the construction industry carries on exactly as it is now: there are some low-carbon projects and we understand the benefit of retrofit, but we have continued to use standard materials because it is easier.

也许第一个问题可能是沙子的短缺。目前，沙子是世界上仅次于水的第二大消耗材料，它也是几种结构材料的基本成分，包括混凝土和玻璃。

Carbon emissions aside, we cannot continue to use concrete the way we currently do – our environment simply cannot support it

But we are running out of it. In some countries this could be an issue as early as next year, but most estimates suggest that by 2050 it will be a significant problem.

To make concrete we need sand that has been shaped by water (rather than wind), but stripping beaches or dredging sand from the ocean floor causes extensive damage as well as accelerating erosion. Carbon emissions aside, we cannot continue to use concrete the way we currently do – our environment simply cannot support it.

其他材料呢?钢筋的重新利用可以节省大量的碳排放，但这种方法的系统和流程相对较新，因此更费力，也更昂贵。相反，我们正在继续用回收钢材制造新的部件，这减少了所需的原始材料，但仍然需要大量的能源来生产它们。

Production of iron and steel contributes to around 7% of global emissions so, if we continue at the same rate, it has a significant impact. But it is also worth considering that this energy requirement has already led to huge rises in the cost of steel as the cost of energy has risen.

If this continues, then it is possible at some point that the cost of new steel will exceed the cost of re-using steel sections. And, if that is the case, isn’t it better to start to get those processes in place now? By 2050 we will most likely have no option but to re-use steel.

One of the biggest contributors to global emissions is road transport and, while private car use makes up a large proportion of this, the transportation of construction materials, as well as site vehicles, also contributes.

Transportation is considered in carbon estimates but in many cases it is a general estimate – carbon savings during production may be cancelled out by the emissions produced during transportation without us even realising. This is only likely to get worse; as materials become more scarce, travel distances could increase considerably, adding to both emissions and costs.

The IPCC report described the next 30 months as the period in which significant changes needed to be made to reduce global emissions

And what will these buildings be like for their users? If we do not manage to reduce global emissions, then temperatures will continue to rise, flooding will increase and air pollution will worsen. This suggests that we might want more cooling in buildings, and we might want to do that in ways that don’t involve opening the windows.

Without the use of natural ventilation, we are adding significantly to the energy use of buildings, and unless we have designed them to generate their own power, then this is likely to be both expensive and add considerably to the whole-life carbon. So, while we are making the inside cooler, we are also making the outside hotter.

The question really is “when is now?” The IPCC report described the next 30 months as the period in which significant changes needed to be made to reduce global emissions. If we consider that the construction industry contributes to around 40% of global emissions, it is clear that we need to make big changes to the way we are working, and we need to do it quickly.

Thirty months takes us to 2025, but we are already designing the buildings that will be constructed in 2025. If we don’t start putting low-carbon design at the top of the agenda we will have missed our chance.

For the construction industry now really does mean now.