What has global warming done since 1998?

What The Science Says:
Every part of the Earth's climate system has continued warming since 1998, with the ten record temperature years all occurring since 2010.

Climate Myth: It hasn't warmed since 1998
For the years 1998-2005, temperature did not increase. This period coincides with society's continued pumping of more CO2 into the atmosphere. (Bob Carter)

At a glance

This date-specific talking-point is now something of a historical curiosity, but we'll leave it in the database for now because it's such a good illustration of the simplistic yet reckless mindset of the serial climate change misinformer. And indeed, we could (out of sheer mischief) have revised this myth by replacing "1998" with "2016". In fact, that's what we started to see in the climate change misinformation stream, © the Usual Suspects. But 2023's record temperatures put a stop to that.

Anyway, as first predicted over a century ago, Earth's surface, oceans and atmosphere are all heating up. That's due to our increasing greenhouse gas emissions, but over the years the warming has occurred at varying rates. This should in no way come as a surprise. Other physical phenomena periodically act either to suppress or enhance temperatures.

A prime example of such a phenomenon is the effects of La Nina and El Nino. This natural climatic oscillation features variations in winds and sea surface temperatures over the tropical eastern Pacific Ocean. The cycle can at times strongly influence temperature and rainfall patterns right around the world.

In a La Nina year, temperatures are suppressed, whereas an El Nino year sees them enhanced. This is noise on the long-term upward trend. That's why climatologists work with multiple decades, not just a few years in isolation, in order to get a grasp on what is going on.

The year 1998 featured a massive El Nino. The temperature spike it caused was a huge outlier, like a pinnacle towering over the landscape of the temperature record. In the following years there was a return to more typical conditions, with an erratic but upward warming pattern. That sequence of events gave deniers a brief opportunity to insist that global warming had “paused” or had even stopped.

You only need to remember one thing here. Those who create and spread misinformation about climate change don't care about reality. Public confusion is their aim. In this instance, the misinformation exercise involved deliberately selecting a limited block of years starting with the massive El Nino of 1998 and using that very warm starting-point to insist that global warming had stopped. They knew this would likely work for a few years and that the public would quickly forget why that was the case. Mother Nature had handed them a gift. It was an irresistible bunch of low-hanging fruit to exploit: little wonder the tactic is known as 'cherry-picking'.

Talking about reality, what actually happened? Well, as of 2024, a couple of decades down the line, the top ten warmest years have all been since 2010, whatever observation-based dataset you choose, with eight of them being in the 2015-2023 period. 1998 is nowhere to be seen any more. By modern standards, it simply wasn't warm enough.

Please use this form to provide feedback about this new "At a glance" section, which was updated on May 27, 2023 to improve its readability. Read a more technical version below or dig deeper via the tabs above!


Further details

Even if we ignore long term trends (something deniers often do in order to make a point) and just look at the record-breakers, as of early 2024 the top ten warmest years have all been since 2010, whatever dataset you choose, with eight of them being in the 2015-2023 period. In this top ten grouping, 1998 is nowhere to be seen any more. It was not warm enough.

The myth of no warming since 1998 was largely based on the satellite record estimates of the temperature of the atmosphere.  However, as discussed in the video below by Peter Sinclair, even that argument is no longer accurate.  The satellites show warming since 1998 too.

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There's also a tendency for some people just to concentrate on atmospheric or surface air temperatures when there are other, more useful, indicators that can give us a better idea how rapidly the world is warming. More than 90% of global warming heat goes into warming the oceans, while less than 3% goes into increasing the atmospheric and surface air temperature.  Records show that the Earth has been warming at a steady rate before and since 1998 and there is no sign of it slowing any time soon (Figure 1). 

Fig 1

Figure 1:  Global Energy Inventory: observed changes in the global energy inventory for 1971–2018 (shaded time series) with component contributions as indicated in the figure legend. Cross-Chapter Box 9.1 Figure 1 (part a) - From IPCC AR6 WGI Chapter 9.

Even if we focus exclusively on global surface temperatures, Cowtan & Way (2013) shows that when we account for temperatures across the entire globe (including the Arctic, which is the part of the planet warming fastest), the global surface warming trend for 1997–2015 is approximately 0.14°C per decade.

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Ultimately, every part of the Earth's climate system is warming, and has continued warming since 1998.


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