diff --git a/platformio.ini b/platformio.ini
index 5c3c4e421..7935eb457 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -149,6 +149,7 @@ lib_deps =
   ClosedCube OPT3001@^1.1.2
   emotibit/EmotiBit MLX90632@^1.0.8
   dfrobot/DFRobot_RTU@^1.0.3
+  sensirion/Sensirion I2C SCD4x@^0.4.0
 
 
   https://github.com/boschsensortec/Bosch-BSEC2-Library#v1.7.2502
diff --git a/src/configuration.h b/src/configuration.h
index 2e0efffd4..79f24453d 100644
--- a/src/configuration.h
+++ b/src/configuration.h
@@ -139,6 +139,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define MLX90632_ADDR 0x3A
 #define DFROBOT_LARK_ADDR 0x42
 #define NAU7802_ADDR 0x2A
+#define SCD4X_ADDR 0x62
 
 // -----------------------------------------------------------------------------
 // ACCELEROMETER
diff --git a/src/detect/ScanI2C.h b/src/detect/ScanI2C.h
index 711e8bee5..de5d2dc34 100644
--- a/src/detect/ScanI2C.h
+++ b/src/detect/ScanI2C.h
@@ -51,7 +51,8 @@ class ScanI2C
         AHT10,
         BMX160,
         DFROBOT_LARK,
-        NAU7802
+        NAU7802,
+        SCD4X
     } DeviceType;
 
     // typedef uint8_t DeviceAddress;
diff --git a/src/detect/ScanI2CTwoWire.cpp b/src/detect/ScanI2CTwoWire.cpp
index 1183d0ddc..85b0001b1 100644
--- a/src/detect/ScanI2CTwoWire.cpp
+++ b/src/detect/ScanI2CTwoWire.cpp
@@ -367,6 +367,11 @@ void ScanI2CTwoWire::scanPort(I2CPort port, uint8_t *address, uint8_t asize)
                 SCAN_SIMPLE_CASE(MLX90632_ADDR, MLX90632, "MLX90632 IR temp sensor found\n");
                 SCAN_SIMPLE_CASE(NAU7802_ADDR, NAU7802, "NAU7802 based scale found\n");
 
+            case SCD4X_ADDR:
+                type = SCD4X;
+                LOG_INFO("SCD4X CO2 sensor found\n");
+                break;
+
             default:
                 LOG_INFO("Device found at address 0x%x was not able to be enumerated\n", addr.address);
             }
@@ -404,4 +409,4 @@ size_t ScanI2CTwoWire::countDevices() const
 {
     return foundDevices.size();
 }
-#endif
+#endif
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index b73d9803b..9a5e24b43 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -583,6 +583,7 @@ void setup()
     SCANNER_TO_SENSORS_MAP(ScanI2C::DeviceType::SHT4X, meshtastic_TelemetrySensorType_SHT4X)
     SCANNER_TO_SENSORS_MAP(ScanI2C::DeviceType::AHT10, meshtastic_TelemetrySensorType_AHT10)
     SCANNER_TO_SENSORS_MAP(ScanI2C::DeviceType::DFROBOT_LARK, meshtastic_TelemetrySensorType_DFROBOT_LARK)
+    SCANNER_TO_SENSORS_MAP(ScanI2C::DeviceType::SCD4X, meshtastic_TelemetrySensorType_SCD4X)
 
     i2cScanner.reset();
 #endif
@@ -1155,4 +1156,4 @@ void loop()
     }
     // if (didWake) LOG_DEBUG("wake!\n");
 }
-#endif
+#endif
\ No newline at end of file
diff --git a/src/mesh/generated/meshtastic/telemetry.pb.h b/src/mesh/generated/meshtastic/telemetry.pb.h
index cedc2867e..bfe4f3fcf 100644
--- a/src/mesh/generated/meshtastic/telemetry.pb.h
+++ b/src/mesh/generated/meshtastic/telemetry.pb.h
@@ -71,7 +71,9 @@ typedef enum _meshtastic_TelemetrySensorType {
     /* MAX17048 1S lipo battery sensor (voltage, state of charge, time to go) */
     meshtastic_TelemetrySensorType_MAX17048 = 28,
     /* Custom I2C sensor implementation based on https://github.com/meshtastic/i2c-sensor */
-    meshtastic_TelemetrySensorType_CUSTOM_SENSOR = 29
+    meshtastic_TelemetrySensorType_CUSTOM_SENSOR = 29,
+    /* SCD40/SCD41 CO2 sensor */
+    meshtastic_TelemetrySensorType_SCD4X = 30
 } meshtastic_TelemetrySensorType;
 
 /* Struct definitions */
@@ -114,8 +116,8 @@ typedef struct _meshtastic_EnvironmentMetrics {
     /* Current measured (To be depreciated in favor of PowerMetrics in Meshtastic 3.x) */
     bool has_current;
     float current;
-    /* relative scale IAQ value as measured by Bosch BME680 . value 0-500.
- Belongs to Air Quality but is not particle but VOC measurement. Other VOC values can also be put in here. */
+    /* relative scale IAQ value as measured by Bosch BME680. value 0-500.
+    Belongs to Air Quality but is not particle but VOC measurement. Other VOC values can also be put in here. */
     bool has_iaq;
     uint16_t iaq;
     /* RCWL9620 Doppler Radar Distance Sensor, used for water level detection. Float value in mm. */
@@ -134,7 +136,7 @@ typedef struct _meshtastic_EnvironmentMetrics {
     bool has_uv_lux;
     float uv_lux;
     /* Wind direction in degrees
- 0 degrees = North, 90 = East, etc... */
+    0 degrees = North, 90 = East, etc... */
     bool has_wind_direction;
     uint16_t wind_direction;
     /* Wind speed in m/s */
@@ -149,6 +151,9 @@ typedef struct _meshtastic_EnvironmentMetrics {
     /* Wind lull in m/s */
     bool has_wind_lull;
     float wind_lull;
+    /* CO2 measured in ppm */
+    bool has_co2;
+    uint16_t co2;
 } meshtastic_EnvironmentMetrics;
 
 /* Power Metrics (voltage / current / etc) */
@@ -267,8 +272,8 @@ extern "C" {
 
 /* Helper constants for enums */
 #define _meshtastic_TelemetrySensorType_MIN meshtastic_TelemetrySensorType_SENSOR_UNSET
-#define _meshtastic_TelemetrySensorType_MAX meshtastic_TelemetrySensorType_CUSTOM_SENSOR
-#define _meshtastic_TelemetrySensorType_ARRAYSIZE ((meshtastic_TelemetrySensorType)(meshtastic_TelemetrySensorType_CUSTOM_SENSOR+1))
+#define _meshtastic_TelemetrySensorType_MAX meshtastic_TelemetrySensorType_SCD4X
+#define _meshtastic_TelemetrySensorType_ARRAYSIZE ((meshtastic_TelemetrySensorType)(meshtastic_TelemetrySensorType_SCD4X+1))
 
 
 
@@ -280,14 +285,14 @@ extern "C" {
 
 /* Initializer values for message structs */
 #define meshtastic_DeviceMetrics_init_default    {false, 0, false, 0, false, 0, false, 0, false, 0}
-#define meshtastic_EnvironmentMetrics_init_default {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
+#define meshtastic_EnvironmentMetrics_init_default {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
 #define meshtastic_PowerMetrics_init_default     {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
 #define meshtastic_AirQualityMetrics_init_default {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
 #define meshtastic_LocalStats_init_default       {0, 0, 0, 0, 0, 0, 0, 0}
 #define meshtastic_Telemetry_init_default        {0, 0, {meshtastic_DeviceMetrics_init_default}}
 #define meshtastic_Nau7802Config_init_default    {0, 0}
 #define meshtastic_DeviceMetrics_init_zero       {false, 0, false, 0, false, 0, false, 0, false, 0}
-#define meshtastic_EnvironmentMetrics_init_zero  {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
+#define meshtastic_EnvironmentMetrics_init_zero  {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
 #define meshtastic_PowerMetrics_init_zero        {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
 #define meshtastic_AirQualityMetrics_init_zero   {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, 0}
 #define meshtastic_LocalStats_init_zero          {0, 0, 0, 0, 0, 0, 0, 0}
@@ -317,6 +322,7 @@ extern "C" {
 #define meshtastic_EnvironmentMetrics_weight_tag 15
 #define meshtastic_EnvironmentMetrics_wind_gust_tag 16
 #define meshtastic_EnvironmentMetrics_wind_lull_tag 17
+#define meshtastic_EnvironmentMetrics_co2_tag 18
 #define meshtastic_PowerMetrics_ch1_voltage_tag  1
 #define meshtastic_PowerMetrics_ch1_current_tag  2
 #define meshtastic_PowerMetrics_ch2_voltage_tag  3
@@ -379,7 +385,8 @@ X(a, STATIC,   OPTIONAL, UINT32,   wind_direction,   13) \
 X(a, STATIC,   OPTIONAL, FLOAT,    wind_speed,       14) \
 X(a, STATIC,   OPTIONAL, FLOAT,    weight,           15) \
 X(a, STATIC,   OPTIONAL, FLOAT,    wind_gust,        16) \
-X(a, STATIC,   OPTIONAL, FLOAT,    wind_lull,        17)
+X(a, STATIC,   OPTIONAL, FLOAT,    wind_lull,        17) \
+X(a, STATIC,   OPTIONAL, UINT32,   co2,              18)
 #define meshtastic_EnvironmentMetrics_CALLBACK NULL
 #define meshtastic_EnvironmentMetrics_DEFAULT NULL
 
@@ -473,4 +480,4 @@ extern const pb_msgdesc_t meshtastic_Nau7802Config_msg;
 } /* extern "C" */
 #endif
 
-#endif
+#endif
\ No newline at end of file
diff --git a/src/modules/Telemetry/EnvironmentTelemetry.cpp b/src/modules/Telemetry/EnvironmentTelemetry.cpp
index 4755a5be5..1a6233370 100644
--- a/src/modules/Telemetry/EnvironmentTelemetry.cpp
+++ b/src/modules/Telemetry/EnvironmentTelemetry.cpp
@@ -30,6 +30,7 @@
 #include "Sensor/NAU7802Sensor.h"
 #include "Sensor/OPT3001Sensor.h"
 #include "Sensor/RCWL9620Sensor.h"
+#include "Sensor/SCD4XSensor.h"
 #include "Sensor/SHT31Sensor.h"
 #include "Sensor/SHT4XSensor.h"
 #include "Sensor/SHTC3Sensor.h"
@@ -54,6 +55,7 @@ AHT10Sensor aht10Sensor;
 MLX90632Sensor mlx90632Sensor;
 DFRobotLarkSensor dfRobotLarkSensor;
 NAU7802Sensor nau7802Sensor;
+SCD4XSensor scd4xSensor;
 #ifdef T1000X_SENSOR_EN
 T1000xSensor t1000xSensor;
 #endif
@@ -139,6 +141,8 @@ int32_t EnvironmentTelemetryModule::runOnce()
                 result = mlx90632Sensor.runOnce();
             if (nau7802Sensor.hasSensor())
                 result = nau7802Sensor.runOnce();
+            if (scd4xSensor.hasSensor())
+                result = scd4xSensor.runOnce();
 #endif
         }
         return result;
@@ -252,6 +256,10 @@ void EnvironmentTelemetryModule::drawFrame(OLEDDisplay *display, OLEDDisplayUiSt
     if (lastMeasurement.variant.environment_metrics.weight != 0)
         display->drawString(x, y += _fontHeight(FONT_SMALL),
                             "Weight: " + String(lastMeasurement.variant.environment_metrics.weight, 0) + "kg");
+
+    if (lastMeasurement.variant.environment_metrics.co2 != 0)
+        display->drawString(x, y += _fontHeight(FONT_SMALL),
+                            "CO2: " + String(lastMeasurement.variant.environment_metrics.co2) + " ppm");
 }
 
 bool EnvironmentTelemetryModule::handleReceivedProtobuf(const meshtastic_MeshPacket &mp, meshtastic_Telemetry *t)
@@ -268,9 +276,9 @@ bool EnvironmentTelemetryModule::handleReceivedProtobuf(const meshtastic_MeshPac
         LOG_INFO("(Received from %s): voltage=%f, IAQ=%d, distance=%f, lux=%f\n", sender, t->variant.environment_metrics.voltage,
                  t->variant.environment_metrics.iaq, t->variant.environment_metrics.distance, t->variant.environment_metrics.lux);
 
-        LOG_INFO("(Received from %s): wind speed=%fm/s, direction=%d degrees, weight=%fkg\n", sender,
+        LOG_INFO("(Received from %s): wind speed=%fm/s, direction=%d degrees, weight=%fkg, co2=%d ppm\n", sender,
                  t->variant.environment_metrics.wind_speed, t->variant.environment_metrics.wind_direction,
-                 t->variant.environment_metrics.weight);
+                 t->variant.environment_metrics.weight, t->variant.environment_metrics.co2);
 
 #endif
         // release previous packet before occupying a new spot
@@ -383,6 +391,10 @@ bool EnvironmentTelemetryModule::getEnvironmentTelemetry(meshtastic_Telemetry *m
             m->variant.environment_metrics.relative_humidity = m_ahtx.variant.environment_metrics.relative_humidity;
         }
     }
+    if (scd4xSensor.hasSensor()) {
+        valid = valid && scd4xSensor.getMetrics(m);
+        hasSensor = true;
+    }
 
 #endif
     return valid && hasSensor;
@@ -433,8 +445,8 @@ bool EnvironmentTelemetryModule::sendTelemetry(NodeNum dest, bool phoneOnly)
         LOG_INFO("(Sending): voltage=%f, IAQ=%d, distance=%f, lux=%f\n", m.variant.environment_metrics.voltage,
                  m.variant.environment_metrics.iaq, m.variant.environment_metrics.distance, m.variant.environment_metrics.lux);
 
-        LOG_INFO("(Sending): wind speed=%fm/s, direction=%d degrees, weight=%fkg\n", m.variant.environment_metrics.wind_speed,
-                 m.variant.environment_metrics.wind_direction, m.variant.environment_metrics.weight);
+        LOG_INFO("(Sending): wind speed=%fm/s, direction=%d degrees, weight=%fkg, co2=%d ppm\n", m.variant.environment_metrics.wind_speed,
+                 m.variant.environment_metrics.wind_direction, m.variant.environment_metrics.weight, m.variant.environment_metrics.co2);
 
         sensor_read_error_count = 0;
 
@@ -568,7 +580,12 @@ AdminMessageHandleResult EnvironmentTelemetryModule::handleAdminMessageForModule
         if (result != AdminMessageHandleResult::NOT_HANDLED)
             return result;
     }
+    if (scd4xSensor.hasSensor()) {
+        result = scd4xSensor.handleAdminMessage(mp, request, response);
+        if (result != AdminMessageHandleResult::NOT_HANDLED)
+            return result;
+    }
     return result;
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/modules/Telemetry/Sensor/SCD4XSensor.cpp b/src/modules/Telemetry/Sensor/SCD4XSensor.cpp
new file mode 100644
index 000000000..a958de3fa
--- /dev/null
+++ b/src/modules/Telemetry/Sensor/SCD4XSensor.cpp
@@ -0,0 +1,57 @@
+#include "configuration.h"
+
+#if !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR
+
+#include "../mesh/generated/meshtastic/telemetry.pb.h"
+#include "SCD4XSensor.h"
+#include "TelemetrySensor.h"
+#include <SensirionI2CScd4x.h>
+
+SCD4XSensor::SCD4XSensor() : TelemetrySensor(meshtastic_TelemetrySensorType_SCD4X, "SCD4X") {}
+
+int32_t SCD4XSensor::runOnce()
+{
+    LOG_INFO("Init sensor: %s\n", sensorName);
+    if (!hasSensor()) {
+        return DEFAULT_SENSOR_MINIMUM_WAIT_TIME_BETWEEN_READS;
+    }
+    // scd4x = SensirionI2CScd4x(nodeTelemetrySensorsMap[sensorType].second);
+    // status = scd4x.begin(nodeTelemetrySensorsMap[sensorType].first);
+    scd4x.begin(*nodeTelemetrySensorsMap[sensorType].second);
+    scd4x.stopPeriodicMeasurement();
+    status = scd4x.startLowPowerPeriodicMeasurement();
+    if (status == 0) {
+        status = 1;
+    } else {
+        status = 0;
+    }
+    return initI2CSensor();
+}
+
+void SCD4XSensor::setup()
+{
+
+}
+
+bool SCD4XSensor::getMetrics(meshtastic_Telemetry *measurement)
+{
+    uint16_t co2, error;
+    float temperature, humidity;
+    error = scd4x.readMeasurement(
+        co2, temperature, humidity
+    );
+    if (error || co2 == 0) {
+        LOG_DEBUG("Skipping invalid SCD4X measurement.\n");
+        return false;
+    } else {
+        measurement->variant.environment_metrics.has_temperature = true;
+        measurement->variant.environment_metrics.has_relative_humidity = true;
+        measurement->variant.environment_metrics.has_co2 = true;
+        measurement->variant.environment_metrics.temperature = temperature;
+        measurement->variant.environment_metrics.relative_humidity = humidity;
+        measurement->variant.environment_metrics.co2 = co2;
+        return true;
+    }
+}
+
+#endif
\ No newline at end of file
diff --git a/src/modules/Telemetry/Sensor/SCD4XSensor.h b/src/modules/Telemetry/Sensor/SCD4XSensor.h
new file mode 100644
index 000000000..0be607e1b
--- /dev/null
+++ b/src/modules/Telemetry/Sensor/SCD4XSensor.h
@@ -0,0 +1,23 @@
+#include "configuration.h"
+
+#if !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR
+
+#include "../mesh/generated/meshtastic/telemetry.pb.h"
+#include "TelemetrySensor.h"
+#include <SensirionI2CScd4x.h>
+
+class SCD4XSensor : public TelemetrySensor
+{
+  private:
+    SensirionI2CScd4x scd4x = SensirionI2CScd4x();
+
+  protected:
+    virtual void setup() override;
+
+  public:
+    SCD4XSensor();
+    virtual int32_t runOnce() override;
+    virtual bool getMetrics(meshtastic_Telemetry *measurement) override;
+};
+
+#endif