How bad is it?
[Updated Dec 2022]
In the Paris Agreement of 2015 the parties agreed that we should try to limit the rise in global temperature to 1.5°C (see Climate recap: key concepts).
To do that we have to reduce our emissions of greenhouse gases until the amount we emit is matched by the amount we remove from the atmosphere. (In practice this means primarily lowering our emissions, since we cannot quickly or easily scale up our ability to remove emissions.20) This is when net emissions become zero, and this needs to happen urgently. Key concepts, such as greenhouse gases, can be found when needed in Climate recap: key concepts.
Over recent years we have seen for ourselves the impacts of global heating, including more intense and frequent wildfires, rainfall and flooding, heatwaves, extreme storms and droughts. There is no corner of the world that is unaffected. Every year that passes these events get worse. In just the first half of 2022 there have been massive floods in Nigeria, Pakistan, India and Bangladesh, severe droughts in Niger, Chad, Ethiopia and Europe, storms in the Philippines and Mozambique and record-breaking heatwaves in India and Pakistan, to name a few.7 Ongoing analysis has shown that many extreme weather events are many times more likely as a result of human-induced climate change.3
The temperatures in the last 7 years to 2021 are the hottest on record,1 and 2022 is on track to make it the last 8 years.8 Around 22 million new and repeated displacements of people were recorded in 2021 as a result of weather-related events; 5.9 million people were still displaced at the start of 2022.2
So in the light of these temperatures and destructive forces just how badly are we doing in our efforts to reduce emissions?
The answer is alarming. As we shall see below, the situation is grave.
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State of our efforts ▼
Greenhouse gas concentrations continued to rise in 2021 (see Figure 2 in key Concepts), and early signs are that this trend is continuing in 2022.
Carbon dioxide (CO2) emissions from fossil fuels and industry have risen each year (excluding 2020) since the Paris Agreement (the red line in Figure 1). They dropped by around 5.2% in 2020 due to Covid-19 travel restrictions, but rebounded immediately in 2021 to almost the same level as before the pandemic.
The rate of growth of CO2 emissions may have slowed in the last decade, but this is small comfort when there is an urgent need to cut emissions substantially. Carbon dioxide emissions are now 40% greater in the decadal average 2010-2019 than in the 1990s when countries first agreed to stabilize emissions, and they are double what they were in the 1960s.
Carbon dioxide contributes around three quarters of all greenhouse gas emissions, but the next largest share is taken by Methane (CH4), which is a far more potent greenhouse gas.6 In 2021 methane concentrations increased by the largest annual amount since 1983 when systematic records began. Concentrations of Nitrous Oxide (N20) were also higher than the average annual growth rate over the previous decade.9 Preliminary estimates of total greenhouse gas emissions in 2021 suggest a new high of 52.8 GtCO2eq 10 excluding the figures from land-use.4
So despite the Paris agreement, we are a long, long way from achieving the urgent reductions we need.
According to the Emissions Gap Report produced by the United Nations Environment Programme the total emissions reduction pledged by governments needs to be seven times higher to keep within 1.5 °C. As things stand, pledges are sufficient only to keep us to 2.4°C assuming there are policies to implement them. But existing policies lead us on a pathway to 2.8°C.12
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Delaying action leaves less time and makes it much harder to keep to 1.5°C ▼
If we delay emission reductions and still want to keep to our 1.5°C heating limit, we have more drastic reductions to make but less time in which to make them.
Substantial reductions are even harder to make in a short time span, even if there is the will. Ultimately this may mean we do not have enough time and we overshoot our budget and, therefore, 1.5°C.
Overshooting 1.5°C risks much worse climate impacts. It also risks uncontrollable warming: this could arise if our capacity to remove carbon at the scale needed doesn’t materialize (see carbon dioxide removal section below), so concentrations continue to rise.
With every week, month or year that we delay making serious reductions in emissions, the greater the reductions have to be, and the more difficult they are to achieve.
For a graphical illustration and a bit of explanation, expand the sections below to see how different ways of reducing emissions affect the time before we reach 1.5°C, and the scale of the challenge as time passes. Hover over the graphs to see how delaying affects the size of reductions (also click on them to make them larger).
Section 1 shows the effects of delay when reductions are spread out evenly over the years. Section 2 shows the effects of delay when drastic reductions are made in early years.
The final subsection, ‘The flipside cannot be emphasized enough‘, contrasts 2 simple cases: we carry on pumping out emissions as we have been doing, or we reduce emissions from 2022.
The graphs use the remaining carbon budget figure estimated by the Intergovernmental Panel on Climate Change (IPCC) in 2020.
1. Delaying leaves less overall time to reduce emissions ▼
Figure 3 shows emission reduction pathways that reduce emissions by a minimum fixed amount each year. The dashed lines represent possible paths in the future.
We can see how the longer we delay before we reduce emissions, the less overall time we have before we use up our budget and get to 1.5°C.
For example, we can see that if we delay reducing emissions until 2026 (the brown line in Figure 3) we reach 1.5°C and net zero (the horizontal axis) by 2032 because we have already used up so much of our carbon budget. This is 7 years earlier than if we start in 2022 (the blue pathway).
Also notice that in order to stay within 1.5°C of warming, the minimum fixed reduction in emissions increases each year that we delay: it rises from 2.2 GtCO2/yr in 2022 to 5.8 GtCO2/yr in 2026. The greater the reduction the harder it becomes to achieve in a shorter time span.
In the next section we show how varying the rate of the reduction (by having bigger reductions in early years) can extend the period before reaching 1.5°C.
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2. Delaying requires even more drastic emission reductions ▼
We can ensure we do not reduce the overall time that we have left to reduce emissions and still keep to 1.5°C, unlike in the previous section. But to do this we have to make much larger reductions in a shorter time span for some of the period. These drastic reductions become harder and harder to achieve in the time.
For example, in Figure 4 the blue and brown pathways are both designed to reach zero net emissions by 2050. But on the brown pathway emissions are not cut until 2026, and this delay comes at a high price.
The reduction in 2026 starts at 9.8 GtCO2 on the brown pathway – almost three times the amount needed if cuts to emissions start in 2022 (blue pathway).
Notice that the initial reductions on both blue and brown pathways in 2026 and 2022 are much higher in Figure 4 than those in Figure 3 since the budget has to last until 2050 in the pathways in Figure 4.
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The flipside cannot be emphasized enough
Starting as early as we can, we have more manageable emission reductions, and more time in which to make them. Figure 5 contrasts a 2022 start with the extreme (but currently plausible) path of continuing to pump out greenhouse gases at our current rate.
The red pathway in Figure 5 shows that by continuing as we have been, we exceed our budget, and the target 1.5°C temperature by 2029.
By contrast, starting to reduce emissions, by just 2 GtCO2 per year in 2022 (on the blue pathway), we have spent 89 GtCO2 less of our carbon budget by 2029.
These budget savings on the blue pathway enable us to continue for another 9 years to 2038 before we exhaust our budget and reach 1.5°C. (This cumulative pathway corresponds to the fixed reduction (blue) pathway in Figure 3).
Residual emissions
The graphical illustrations above (Figures 3, 4 and 5) are simplified to demonstrate the effect of delaying serious reductions in emissions. They illustrate pathways that descend to zero CO2 emissions. However, in practice, there are likely to be some annual residual emissions that are hard to remove, such as those from cement and steel manufacture.
Residual emissions would, therefore, need to be removed to prevent further accumulation of CO2 in the air and further warming. For instance, if we had 5GtCO2 annually of residual emissions, we would need to have expanded our sinks, such as forests, to remove the extra 5GtCO2 a year and get to net zero.
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Reducing net emissions takes time to implement ▼
Few of the measures to reduce emissions and stop the temperature rising are quick to implement. It takes time to build the renewable energy power plants that we need; It takes time to build storage for the energy generated; it takes time to electrify our public transport, insulate public buildings and conduct research.
And some things just cannot be hurried: trees take a while to grow enough to be effective at removing CO2 from the air.
So with less time available we may not have enough time to implement the measures needed to get to zero net emissions, and to stop the global temperature rising above 1.5°C. And if governments, corporations and individuals continue to show inertia in cutting emissions, we will not be able to avoid exceeding 1.5°C and maybe 2, 3 or 4°C, and the more severe impacts that go with higher temperatures.
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If we delay, we also have less time to adapt to the impacts of warming ▼
With an earlier rise in temperature from 1.2°C, which it is now, to 1.5°C, there is likely to be more flooding earlier, more crop failures, more droughts, heatwaves, wildfires, and cyclones earlier. And they are likely to be more intense than they are now.13
We can no longer avoid the impacts that are coming with a global average temperature of 1.5°C. But getting to 1.5°C earlier leaves us less time to build coastal and riverside defences, adapt homes, and change to drought-tolerant crops. We need time to diversify skills, improve early warning systems, and implement vaccination programmes against the rise in diseases.14
Time is critical for low-lying countries that are more vulnerable to flooding, and drought-prone regions where people are dependent on their crops to survive. Without the time to adapt, many people will lose their homes, livelihoods and maybe their lives. Many more people will be displaced.
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Can we still do it?
We have the technology and the ability to achieve our target temperature, but it needs fast and radical change for it to happen.
The lack of a timely and adequate response by governments and corporations has made our situation desperate. Individual action to reduce personal emissions has always been needed to get to net zero. But now it is crucial that we do as much as we can, and as fast as we can. We cannot wait for governments and corporations to act.
Our actions can have immediate effect on emissions, since we are not hampered by bureaucracy or the need to have our actions approved. And together, in sufficient numbers, we have the power to influence the policies of the governments and corporations that continue to fuel the climate crisis: by withdrawing our custom, corporations lose their profits, and political parties can lose our votes and support.
If each of us focuses on starting right now, and doing all that we can to reduce our emissions, several billion of us should be enough to have an impact, especially those of us in industrialized countries.
If we talk about the changes we make, share our actions on social media, and put up posters in our neighbourhoods to publicize earth’s urgent need, we can also motivate many more to increase our numbers so that we can help our world together.
To start now, go to What can I do? to see what actions you can take and how to achieve them, or go straight to the Pledges page, which links to appropriate sections in ‘What can I do?’.
