Prime Minister for Canyons wrote on Apr 18^th, 2017 at 2:28pm:



Yes. I saw that.

From your reference -

"Setting the scene... an update on the age of the Reef

We have sourced the latest information available on the age of the Great Barrier Reef. Stay tuned though, because we’re
expecting this information to change as more research is undertaken.

These are the significant dates you should be talking about when explaining the age of the Great Barrier Reef:
•  While corals have existed on the Great Barrier Reef for as long as 25 million years, they didn’t form large structured reefs like those we see today.
•  The earliest record we have of complete reef structures (like those we see today) is from 600 000 years ago."

So that is about the Great Barrier Reef (GBR). So these new "structured reefs", how did they form? Are they any different from other world reefs?

ENSO neutral, but tropical Pacific waters continue to warm
The El Niño–Southern Oscillation (ENSO) remains neutral. However the Bureau's ENSO Outlook is currently at El Niño WATCH, meaning there is around a 50% chance—twice the normal likelihood—of El Niño developing in 2017.
Tropical Pacific sea surface temperatures (SSTs) have warmed since the start of the year. SSTs in the central tropical Pacific are now 0.5 °C warmer than average, still below the +0.8 °C threshold for El Niño levels. Atmospheric indicators of ENSO remain firmly neutral, although the Southern Oscillation Index (SOI) has returned to negative values over the past fortnight.

International climate models suggest the tropical Pacific Ocean is likely to continue warming in the coming months, though in recent weeks some models have reduced the expected extent of warming. Five of eight models indicate that sea surface temperatures will exceed El Niño thresholds during the second half of 2017; a reduction of two models since the last Wrap-Up release. It should be noted that models have lower accuracy at this time of year.

El Niño is often, but not always, associated with below average winter–spring rainfall over eastern Australia. Of the 27 El Niño events since 1900, 18 resulted in widespread dry conditions for parts of Australia.

The Indian Ocean Dipole (IOD) is currently neutral. Four out of six climate models suggest a positive IOD is likely during winter. When a positive IOD coincides with El Niño, the typical El Niño dry signal expands, and generally stretches further west over eastern and central Australia.

Models reduce likelihood of El Niño for 2017 but tropical Pacific Ocean warmer than average.

The tropical Pacific is currently El Niño–Southern Oscillation (ENSO) neutral. Despite the likelihood for El Niño easing in some models, an event in 2017 cannot be ruled out. The Bureau's ENSO Outlook remains at El Niño WATCH, meaning there is around a 50% chance that El Niño may develop in the coming months.

Sea surface temperatures in the tropical Pacific Ocean have warmed since the start of the year, but remain below El Niño thresholds. Some other atmospheric indicators have shifted over the past fortnight, but also remain below El Niño levels.

Some international climate models have reduced the likelihood of El Niño this year compared to last month. However, five of eight international climate models still indicate the tropical Pacific Ocean may exceed El Niño thresholds during the second half of 2017. It should be noted that models have lower accuracy forecasting El Niño through the autumn months.

Pretty good at this stage of an El Nino year.

Just reporting is all. That downgrade is fairly meaningless this far out anyway.